UC-NRLF 


B    3 


WASHINGTON  UNIVERSITY, 

Theses  for  the  Degree  of  Doctor  of  Philosophy, 


Xo.    6. 


A  DISEASE  OF  TAXODIUM  KNOWN  AS  PECKIXESS, 

ALSO  A  SIMILAR  DISEASE  OF  LIBOCEDRUS 

DECURRENS. 


HERMANN    VON    S(  HRKNK. 
B.  S..  Cornell   (  Harvard  Univ. 

!!andidal 


St.  Louis.  Mo.,  .hint'  1.  istH). 


SCIENTIFIC  PAPEES. 


A  DISEASE  OF  TAXODIUM  DISTICHUM  KNOWN  AS  PECKI- 
NESS,  ALSO  A  SIMILAR  DISEASE  OF  LIBOCEDRUS  DECUR- 
RENS  KNOWN  AS  PIN-ROT.* 

BY   HERMANN   VON   SCHRENK. 
INTRODUCTION. 

The  diseases  of  forest  trees  had  attracted  attention  for 
many  years  before  any  attempt  was  made  to  arrive  at  an 
understanding  of  their  true  nature.  With  the  investigations 
of  Th.  Hartig,  t  Schacht,J  and  Willkomm,§  a  beginning  was 
made,  but  not  until  the  epoch-making  researches  of  R. 
Hartig,  ||  were  some  of  the  complex  relations  between 
diseased  trees  and  the  exciting  causes  made  clear.  In 
England,  Marshall- Ward  has  paid  some  attention  to  the 
diseases  of  trees,  but  in  this  country  few  have  given  this 
subject  much  study. 

A  tree  may  be  diseased  because  of  the  natural  decadence 
of  its  vital  forces  incident  to  old  age,  it  may  be  influenced 
by  abnormal  physiological  conditions,  or  its  functions  may 
be  impaired  by  the  activities  of  a  disturbing  organism. 

*  A  thesis  presented  to  the  Faculty  of  Washington  University  for  the 
degree  of  Ph.  D.,  April,  1899. 

t  Hartig,  Th.  Abhandlung  iiber  die  Verwandlung  der  polycotyle- 
donischen  Pflanzenzelle  in  Pilz  u,  Schwammgebilde,  u.  die  daraus 
hevorgehende  Faulniss  des  Holzes.  1833. 

t  Schacht,  Hermann.  Der  Baum,  Studieu  iiber  Bau  u.  Leben  der 
hoheren  Gewachse.  Berlin.  1860. 

§  Willkomm,  M.  Die  mikroscopischen  Feinde  des  Waldes.  Dresden. 
1866. 

||  Hartig,  R.  Wichtige  Krankheiten  der  Waldbaume.  Berlin.  1874.— 
Die  Zersetzungserscheinungen  des  Holzes,  etc.  Berlin.  1878. 

Separates  issued  June  3, 1899.  1 


166218 


MISSOURI   BOTANICAL    GARDEN. 

j> 

Examples  of  the  first  class  of  disease  need  not  be  given ; 
the  root  rot  of  pines  *  is  an  example  of  the  second  class, 
and  the  numerous  fungi  (and  insects)  attacking  different 
parts  of  a  tree  come  under  the  third  class.  It  is  particu- 
larly the  latter  class  which  Hartig  has  studied  and  with 
some  of  which  the  present  paper  is  to  deal. 

The  fungi  attacking  trees  may  be  divided  for  convenience 
into  such  as  are  strictly  parasitic,  like  the  Peridermiums, 
Exoasci,  Gymnosporangiums,  etc.,  and  such  as  are  not. 
Among  the  latter  class  one  finds  various  grades,  going  from 
the  strictly  parasitic  to  the  strictly  saprophytic  forms, 
including  the  facultative  saprophytes  (of  De  Bary)  or 
hemiparasites,  the  true  saprophytes,  and  the  facultative 
parasites  (De  Bary),  or  hemisaprophytes.  Of  the  fungi 
which  attack  the  trunks  of  trees,  i.  e.,  the  wood  already 
formed,  few  are  strictly  parasitic  or  hemiparasitic ;  the 
majority  are  hemisaprophytes,  for  although  normally 
growing  on  dead  matter  they  may  occasionally  become 
truly  parasitic.  Tubeuf  f  mentions  a  number  of  such  fungi, 
among  them  several  common  in  this  country,  such  as 
Trametes  Pini,  Polyporus  fomentarius ,  Polyporus  sul- 
phureus,  and  others.  Trametes  Pini  may  serve  as  a  good 
example.  When  growing  on  species  of  pine,  such  as  Pinus 
palustris,  Pinus  Strobus,  Pinus  echinata,  it  flourishes  in 
the  heartwood  of  these  trees  as  a  strict  saprophyte,  i.  e., 
on  the  dead  wood.  The  resinous  contents  of  the  living 
wood  prevent  its  becoming  parasitic.  On  the  other  hand, 
when  growing  on  Abies  balsamea  or  Picea  nigra  it  becomes 
a  parasite,  growing  likewise  in  the  living  wood  and  ulti- 
mately killing  the  tree.  The  diseases  to  be  discussed  in 
the  following  are  due  to  hemisaprophytes,  as  they  affect  the 
heartwood  of  the  trees  and  never  enter  the  living  parts  of 
the  trunks. 

*  Hartig,  R.    Zersetzungserscheinungen,  etc.  75. 
t  Tubeuf,  C.  Freiherr  von.    Diseases  of  plants  5.     (English  edit,  by 
W.  G.  Smith.     1897.) 
2 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

Some  years  ago,  while  collecting  in  the  cypress  swamps 
of  Arkansas,  a  peculiar  defect  of  the  bald  cypress,  Taxodium 
distichum,  was  noticed,  popularly  known  as  "pecky"  or 
"  Peo£v  "  cypress.  Further  investigation  showed  that  the 
defect  was  prevalent  wherever  the  cypress  grew  in  abun- 
dance, and  that  fungus  threads  were  constantly  associated 
with  the  pecky  wood.  This  led  to  the  investigations  here 
recorded. 

In  pursuing  these  investigations  little  could  have  been 
done  without  the  generous  assistance  of  numerous  lumber 
companies.  Among  those  to  whom  thanks  are  due  are  the 
Lutcher  &  Moore  Cypress  Lumber  Co.  of  Lutcher,  La. ; 
Mr.  M.  E.  Leniingof  Cape  Girardeau,  Mo. ;  Towle  Bros,  of 
Towle,  Placer  Co.,  Cal. ;  the  Stimson  Mill  Co.  of  Ballard, 
Wash.;  Mr.  A.  J.  Johnson  of  Astoria,  Oregon,  and  Birce 
&  Smart  of  Emigrant  Gap,  Cal. 

To  Dr.  W.  G.  Farlow  and  Dr.  H.  W.  Harkness  I  am 
indebted  for  many  suggestions;  to  Dr.  J.  J.  Friih  of 
Zurich,  for  his  courtesy  in  answering  some  questions;  to 
Maj.  B.  M.  Harrod  of  New  Orleans  for  assistance  in 
obtaining  buried  cypress  logs,  and  to  Prof.  C.  K.  Sanger 
and  Dr.  G.  Alleman  for  suggestions  on  chemical  questions. 
I  also  take  pleasure  in  expressing  thanks  to  Dr.  Wm. 
Trelease  for  much  encouragement  and  generous  assistance. 


THE    DISEASE    OF   TAXODIUM    KNOWN   AS  "  PECKY  "    CYPRESS. 

HISTORICAL. 

The  first  mention  of  the  disease  of  cypress  known  as 
"  pecky,"  or  "  peggy  "  cypress,  is  made  by  Dickeson  & 
Brown.*  They  say  of  it :  "  That  species  of  decay  to  which 
it  [the  cypress]  is  most  liable,  shows  itself  in  partial  or  de- 
tached spots  at  greater  or  less  distance,  but  often  in  very 
close  proximity  to  each  other.  It  is  a  decomposition  of  the 

*  Dickeson,  Montroville  W.,  &  And.  Brown.  On  the  cypress  timber  of 
Mississippi  and  Louisiana.  (Am.  Journ.  of  Science,  ii.  5  : 15.  1848.) 


MISSOURI   BOTANICAL    GARDEN. 

wood  fiber  to  which  the  tops  and  central  parts  are  the  most 
exposed,  and  which,  when  affected,  appear  as  if  operated 
upon  by  worms.  .  .  .  Timber  affected  in  this  way  is 
denominated  by  raftsmen,  «  pecky.'  ' 

Sargent*  says  of  the  cypress:  "  It  is  often  injured, 
especially  west  of  the  Mississippi  river,  by  a  species  of 
Daedalea  not  yet  determined, rendering  it  unfit  for  lumber." 
Farlow,f  writing  in  Sargent's  Silva,  notes  that  "  a  species 
of  dry  rot  in  living  timber  often  diminishes  its  value,  and 
in  Louisiana  and  Mississippi  is  said  to  affect  at  least  one- 
third  of  all  the  trees."  Bather  recently  Roth  J  mentions 
its  occurrence  in  the  South,  and  briefly  describes  its  appear- 
ance. Beyond  these  few  notes,  nothing  appears  to  have 
been  said  of  the  disease. 

OCCURRENCE. 

Taxodium  distichum  is  now  found  from  South  Carolina 
to  Florida  (some  trees  occur  as  far  north  as  New  Jersey  §) 
thence  to  Louisiana  and  northward  as  far  as  southern  Indiana  If 
and  southeast  Missouri.  Wherever  the  cypress  grows  to 
any  size,  it  shows  the  "  pecky  "  disease,  the  prevalence  of 
which  appears  to  be  very  variable.  The  exact  percentage  is 
difficult  to  ascertain  as  it  varies  materially  with  the  locality. 
Roth  (1.  c.)  says  that  30%  of  the  entire  cypress  supply  is 
damaged  by  this  disease.  As  a  rule  one  may  say  that 
wherever  the  cypress  grows,  one  will  find  it  "  pecky,"  and 
that  there  are  no  regions  where  all  trees  are  sound.  As 
for  particular  localities,  Roth  mentions  a  tract  of  land  in 
Florida,  which  had  to  be  abandoned  entirely  on  account  of 
"  pegginess."  In  the  Mississippi  Valley  by  actual  count  it 

*  Sargent,  C.  S.  Forest  trees  of  North  America.  10th  Census 
9:184.  1883. 

t  Sargent,  C.  S.     Silva  of  North  America  10 : 150.     1896. 

J  Roth,  Filibert.  Progress  in  timber  physics — "  Bald  cypress." 
(U.  S.  Dept.  of  Agr.,  Div.  of  Forestry,  Circular  No.  19:  3.  1898.) 

§  Hollick,  A.     (Cypress  in  N.  J.,  read  before  Bot.  Soc.  Am.     1898.) 

f  Wright,  John  S.  —Notes  on  cypress  swamps  in  Knox  Co.,  Indiana. 
(Proc.  Ind.  Acad.  Sci.  1897  : 172). 
4 


DISEASES    OF    TAXODIUM    AXD    LIBOCEDRUS. 

has  beenfound  that  the  trees  near  their  northern  limit  are  less 
frequently  diseased  than  the  more  southern  ones.  As  it  is  al- 
most impossible  to  tell  whether  a  tree  be  pecky  or  not  before 
it  is  cut  down,  all  actual  counts  had  to  be  made  where  lumber 
mills  were  cutting  the  trees,  and  as  they  usually  cut  all 
trees,  even  those  liable  to  be  diseased,  a  fair  estimate  for  that 
particular  locality  could  be  made.  In  St.  James  Parish, 
Louisiana,  397  trees  out  of  400  were  found  diseased  to  a 
greater  or  less  extent.  From  circulars  sent  to  various  lum- 
ber concerns  the  following  estimates  are  made,  which  may 
be  considered  as  much  under-  rather  than  overdrawn. 
Apalachicola,  Fla.,  10—15%.  New  Orleans  Cypress  Lum- 
ber Co.,  99%.  Kamos,La.,  15%.  Georgetown,  S.C.,  "  con- 
siderable. ' '  These  figures  refer  to  « «  peckiness  ' '  in  logs  used 
for  lumber,  and  do  not  have  any  reference  to  the  tops  of 
trees,  which  are  the  first  parts  to  be  "  pecky."  The  char- 
acter of  the  ground  seems  to  have  little  if  any  effect  on  the 
prevalence  or  extent  of  the  disease.  The  cypress  trees 
normally  grow  with  their  root  system  in  water  for  at  least  a 
part  of  each  year,  and  in  many  places,  particularly  along  the 
coast,  during  the  entire  year.  This  rather  unusual  habit  of 
growth  together  with  the  appearance  of  the  puzzling  form- 
ation of  knees  has  led  many  to  connect  the  facts  of  growing 
in  water,  development  of  knees,  and  "  peckiness."  So  far 
no  evidence  is  forthcoming  to  show  any  connection  between 
these  factors. 

NAME. 

When  a  diseased  cypress  tree  is  cut  down,  the  heart  wood 
appears  as  if  a  large  number  of  holes  had  been  bored  with 
a  -J-  inch  bit  which  had  been  withdrawn,  leaving  the  shav- 
ings, finely  divided,  within  the  hole.  It  is  this  peculiar  ap- 
pearance which  has  given  rise  to  the  different  popular  terms 
applied  to  the  disease.  Dickeson  &  Brown  (1.  c.)  refer  to 
it  as  "  pecky."  In  the  Mississippi  Valley  and  throughout 
Louisiana  I  have  found  the  diseased  wood  called  *  <  pecky  ' ' 


MISSOURI   BOTANICAL    GARDEN. 

cypress,  and  the  disease  itself  called  the  « *  peck. ' '  In  North 
Carolina  the  term  "  botty  "  (see  Roth  1.  c.)  is  more  or  less 
common  because  of  the  supposed  action  of  a  larva,  the 
* «  bot. ' '  *  'Peggy  ' '  is  frequently  used  in  Georgia  and  Flor- 
ida, where  correspondents  also  give  the  term  « '  puck. ' '  Near 
pinelands  "  punk  "  is  used  by  pine  lumbermen,  accustomed 
to  the  decay  caused  by  Trametes  Pini.  It  is  almost  useless  to 
speculate  as  to  the  origin  of  the  various  terms,  and  a  choice 
between  them  is  difficult.  Having  found  the  term  < «  pecky  ' ' 
most  widely  known  as  well  as  the  one  which  was  first  used, 
I  shall  call  the  disease  by  that  name  throughout  this  paper. 

APPEARANCE  OF  WOOD. 

The  diseased  wood  appears  full  of  holes  (PL  1,  fig.  2), 
varying  in  width  from  -J— J-  inches.  These  holes  are  found 
in  the  heartwood  only,  and  in  trees  after  they  have  reached 
the  age  of  125  years  or  thereabouts.  Young  trees  of 
Taxodium  are  comparatively  rare,  but  such  as  were  noted, 
varying  in  age  from  50  to  125  years,  were  always  free  from 
any  defect.  The  holes  in  the  wood  extend  longitudinally 
up  and  down  in  the  trunk,  parallel  to  the  wood  fibers.  The 
holes  never  extend  transversely.  They  are  separated  from 
one  another  by  layers  of  wood  apparently  perfectly  sound. 
They  vary  in  length  from  }  inch  to  6  inches,  or  longer 
in  some  cases;  most  frequently  they  are  4-5  inches 
long.  They  end  bluntly  at  both  ends,  and  as  a  rule  do  not 
communicate.  Frequently  trees  are  found  in  which  some 
holes  do  open  into  one  another,  but  these  are  rather 
exceptional.  The  holes  are  filled  with  a  yellow  brown 
powder  which  readily  crumbles  into  the  finest  dust  between 
the  fingers.  The  powdery  mass  does  not  completely  fill 
the  space,  showing  that  much  material  has  been  destroyed. 
Occasionally  the  mass  is  not  entirely  composed  of  the 
powdery  substance;  stringy  fibers,  composed  of  wood  cells 
not  yet  disintegrated,  fill  the  cavity,  together  with  much 
finely  divided  matter.  This  indicates  that  the  disintegrat- 
6 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

ing  factor  has  not  acted  uniformly  but  has  caused  certain 
parts  to  decay,  while  others  are  spared.  A  fluffy  white 
fungus  mycelium,  covered  with  drops  of  liquid  as  with 
dew,  is  oftentimes  present,  but  more  often  none  is  to  be 
seen  amid  the  dry  contents  of  the  holes.  Several  trees 


APPEARANCE  OF  WOOD. 

were  found  near  Mobile,  Ala.,  in  which  the  holes  were 
partially  filled  with  a  peculiar  reddish-brown,  soft  sub- 
stance having  a  bright  shining  fracture.  This  substance 
adhered  firmly  to  the  walls,  as  if  forming  a  part  of  the 
wood  fibers.  It  will  be  described  more  in  detail.  Asso- 
ciated with  this  substance  peculiar  white  needle-shaped 

7 


MISSOURI    BOTANICAL    GARDEN. 

crystals  were  found  whose  identity  has  not  yet  been  deter- 
mined, as  the  amount  found  was  too  small  to  admit  of 
analysis.  This  substance  had  the  following  properties: 
very  light,  like  fine  cotton  wool,  or  cocoon  silk,  apparently 
very  pure;  volatilizes  at  once  on  platinum  (heated)  with- 
out burning;  insoluble  in  water,  soluble  in  hot  alcohol, 
from  which  it  crystallizes  in  shapes  looking  like  sea  moss ; 
very  soluble  in  petroleum  ether,  and  extremely  so  in  chlo- 
roform; residue  colloid,  resinous;  melting  point  174°  C., 
pretty  sharp  without  decomposition;  chloroform  solution 
does  not  absorb  bromine;  sublimes  very  readily,  forming 
beautiful  hairlike  crystals. 

A  number  of  trees  were  found  in  which  the  holes,  instead 
of  being  filled  as  stated  above,  were  nearly  empty.  They  had 
a  shining  white  lining  (  PI.  4,  fig.  3)  from  which  isolated 
white  fibers  projected  into  the  cavity.  The  white  fibers  were 
found  to  be  pure  cellulose. 

When  the  brown  contents  are  brushed  out  of  the  holes  a 
perfectly  even  and  smooth  surface  is  left  on  all  sides,  indi- 
cating a  very  sharp  dividing  line  between  the  decayed  ele- 
ments and  those  apparently  sound.  A  board  from  which 
the  powder  has  been  taken  looks  as  if  a  number  of  grooves 
had  been  cut  with  a  gouge  chisel  (PI.  6). 

In  a  tree  the  peckiness  starts  in  the  upper  part,  i.  e.,  the 
majority  of  the  trees  are  perfectly  sound  at  the  base,  and 
very  much  diseased  in  the  upper  portion  of  the  trunk  and 
the  larger  branches.  The  decay  may  extend  but  a  few 
inches  up  and  down,  or  for  several  feet,  or  through  the 
entire  length  of  the  tree.  The  youngest  branches  in  which 
any  peckiness  was  found  were  60  years  old.  Eadially  it 
may  appear  over  the  entire  cross-section  or  on  but  one  side. 
It  is  by  no  means  the  rule  that  the  innermost  rings 
are  the  first  ones  to  decay  (PI.  1)  as  might  be  supposed 
from  analogy  with  other  timber  diseases.  A  large  tree  at 
Arbor,  Mo.,  approximately  300  years  old,  was  pecky  to 
within  25  ft.  of  the  base,  another  to  within  35  ft.  The 
8 


DISEASES    OF    TAXODIUM   AND    LIBOCEDRUS. 

peckiness  in  the  latter  extended  upward  into  two  main 
branches  for  20  ft.  At  the  points  where  all  recognizable 
traces  of  the  disease  ceased,  the  branches  had  about  150 
annual  rings.  A  third  tree  was  sound  for  60  ft.  from  the 
base,  then  became  very  pecky,  the  peckiness  passing  up 
into  two  or  three  main  branches,  and  still  another  was  pecky 
3  ft.  from  the  base  and  upward.  The  extent  of  peckiness 
varies,  i.  e.,  in  one  trunk  the  holes  may  be  several  inches 
apart,  or  scattered  all  over  the  cross-section,  in  another  they 
may  be  confined  to  the  first  150  rings.  Nowhere  was  a 
single  tree  seen  hollow,  at  least  none  which  was  hollow  be- 
cause of  an  advanced  stage  of  peckiness.  In  this  respect 
this  disease  affects  the  cypress  just  as  Trametes  Pini  does 
the  pines.  One  never  finds  a  pine  hollow  because  of 
disintegration  caused  by  Trametes  Pini.  This  is  especially 
to  be  noted,  as  it  will  be  referred  to  again.  It  is  a  notice- 
able fact  that  in  traveling  through  cypress  forests  one 
rarely  sees  many  fallen  trees,  and  where  violent  wind- 
storms have  overthrown  any  number  of  trees,  these  are  just 
as  often  trees  sound  at  the  base  as  those  which  are  diseased. 
In  the  fall  the  whole  tree  falls,  i.  e.,  the  trunk  does  not 
break,  as  do  many  pines  and  deciduous  trees,  in  which  the 
entire  heartwood  may  have  been  destroyed,  by  such  a  para- 
site as  Polyporus  sulphureus.  The  oldest  trees  e.  g.,  in 
which  about  1800  rings  were  counted  (southern  Louisiana), 
have  the  same  appearance  as  those  but  200-300  years  in  age. 

STRUCTURE  OF  DISEASED  WOOD. 

The  wood  of  Taxodium  is  composed  of  tracheids  with 
one  or  two  rows  of  pits.  The  growth  rings  are  rather  broad, 
the  summer  wood  about  one-third  the  width  of  the  spring 
wood.  Kesin  passages  are  wholly  wanting,  and  in  their 
stead  there  are  numerous  resin  cells  either  scattering  or  in 
tangential  bands.*  The  amount  of  resin  in  the  wood  is 

*  Penhallow,  D.  P.  The  generic  characters  of  the  N.  A.  Taxaceae  and 
Coniferae.  (Trans.  Roy.  Soc.  Canada  ii.  2  :  51.  1896.) 

9 


MISSOURI    BOTANICAL    GARDEN. 

comparatively  small.  The  diseased  wood  is  darker  in  color 
than  the  normal  wood,  has  no  tenacity,  and  when  crushed, 
turns  into  fine  powder.  These  properties  lead  one  to  sus- 
pect profound  morphological  as  well  as  chemical  changes. 
A  radial  section  through  a  'rotted  hole  and  the  adjacent 
sound  wood  is  represented  on  PI.  5,  fig.  10.  The  normal 
wood  cells  (a)  show  the  constituent  lamellae  of  the 
cell- wall  plainly.  The  first  noticeable  change  is  in  the  bor- 
dered pits,  which  look  as  if  they  were  corroded,  like  starch- 
grains  in  process  of  solution.  This  appearance  is  due  to 
drops  of  resinous  oil,  which  arrange  themselves  in  this 
peculiar  manner  (PI.  5,  fig.  3)  on  the  walls  and  within 
the  cavity  of  the  pit.  When  treated  with  turpentine  the 
resin  is  dissolved  and  the  pits  then  look  smooth.  The  walls 
at  the  same  time  are  perforated  in  many  places  by  colorless 
hyphae;  no  preference  is  shown  for  the  pits.  As  one  pro- 
ceeds toward  the  decayed  spot  the  pits  look  fragmented ;  fin- 
ally peculiar  spiral  breaks  appear  extending  from  the  pits  and 
passing  upward  from  left  to  right.  The  breaks  of  two  adja- 
cent walls  cross  one  another  at  the  pits  (e),  the  lower  one 
apparently  extending  from  right  to  left.  The  whole  cell- 
wall  becomes  striated,  the  striae  all  extending  in  a  spiral  line 
from  left  to  right  around  the  wall.  Before  long  the  circu- 
lar disc  of  the  pit  drops  out,  leaving  a  hole  with  jagged 
outline,  which  gradually  increases  in  size.  The  number  of 
breaks  in  the  walls  has  increased,  and  finally  the  whole  wall 
breaks  up  into  innumerable*  pieces.  The  wood,  when  once 
the  disintegration  sets  in,  becomes  so  very  brittle  that  it  is 
very  difficult  to  get  good  sections.  Imbedding  the  same  in 
soft  paraffine  was  found  very  useful.  The  longitudinal 
walls  grow  thinner  because  of  the  shrinkage  of  the  middle 
lamella.  This  gradually  disappears,  and  gives  rise  to  the 
breaks  in  the  wall  already  spoken  of.  The  shrinkage  and 
solution  finally  has  gone  so  far  that  only  the  primary 
lamella  is  left,  which  breaks  into  many  pieces.  The  drop- 
ping out  of  the  more  resistant  walls  lining  the  pits  is  char- 
10 


DISEASES    OF    TAXODIUM   AND    LIBOCEDRUS. 

acteristic,  and  in  preparations  of  much-decayed  wood  large 
numbers  of  the  circular  discs  can  be  seen  floating  about. 

The  micro-chemical  reactions  are  marked.  Any  investi- 
gation into  the  chemical  nature  of  wood  substance  is  apt  to 
be  rather  unsatisfactory.  It  is  possible  to  record  certain 
well-marked  reactions,  but  often  their  true  significance  will 
not  be  apparent,  because  our  knowledge  of  the  complex 
constituents  of  wood,  and  particularly  of  its  decomposition 
products,  is  still  so  very  meager. 

The  most  characteristic  reaction  is  the  one  with  phloro- 
glucin  and  HC1.  If  a  section,  preferably  a  transection 
of  wood  cut  so  as  to  include  the  outer  portion  of  the 
decayed  area,  and  some  of  the  surrounding  wood,  be  treated 
with  this  reagent,  an  appearance  such  as  is  represented  on 
PI.  3,  fig.  1,  is  obtained.  The  cells  of  the  sound  wood 
i.  e.,  wood  in  which  no  recognizable  morphological 
change  has  taken  place,  stain  dark  red  purple.  The  pri- 
mary lamella  stains  much  deeper  (p).  Passing  to  cells 
further  inward  (towards  the  diseased  spot)  the  tertiary 
lamellae  of  some  cells  no  longer  stain  red  purple  but  yellow 
(d).  This  yellow  coloration  increases  as  one  passes  on,  the 
red  decreasing  correspondingly,  until  at  a  certain  stage 
only  the  primary  lamella  is  stained  red.  The  pits  are  the 
first  areas  to  show  the  yellow  color.  On  a  radial  longitu- 
dinal section  the  contrast  between  the  surrounding  wall  and 
the  pit  is  very  marked,  the  latter  looking  like  a  hole  in  a  red 
field.  In  the  final  stage  the  remaining  parts  are  entirely 
yellow,  no  red  being  visible.  The  yellow  coloration  appears 
first  along  the  medullary  rays,  and  is  always  in  advance  of 
the  same  reaction  in  the  intervening  wood  cells.  Hand  in 
hand  with  the  disappearance  of  the  red  color  goes  the 
shrinkage  of  the  secondary  lamella,  as  described.  This 
reaction  of  the  cell-wall  is  due  to  the  gradual  extraction  of 
the  coniferin  elements  of  the  walls.  They  are  at  first 
extracted  from  the  innermost  lamella,  then  from  the 
secondary  lamella,  and  last  of  all  from  the  primary 

11 


MISSOURI    BOTANICAL    GARDEN. 

lamella  and  the  intercellular  substance  at  the  angles 
of  the  cells.  If  a  similar  section  is  treated  with  chlor- 
iodide  of  zinc  the  walls  of  sound  wood  cells  are  col- 
ored yellow-brown.  The  cells  from  which  the  lignin  ele- 
ments have  been  removed  stain  brown  likewise.  This 
indicates  that  they  are  not  cellulose.  In  this  respect  the 
disintegration  of  the  cypress  wood  differs  from  that  caused 
in  wood  of  the  yellow  pine  by  Trametes  Pini.  In  the  latter 
there  is  one  form  of  disintegration  in  which  the  lignin  ele- 
ments are  gradually  removed  from  the  cell-wall,  beginning 
with  the  secondary  lamella,  closely  followed  by  the  tertiary 
lamella.  After  this  extraction  a  much  thinner  wall  of  pure 
cellulose  remains.  Some  cases  were  found  in  wood  of 
Pinus  echinata,  however,  which  could  not  be  distinguished 
from  pecky  cypress,  i.  e.,  after  the  extraction  of  the  lignin 
elements,  as  indicated  by  phloroglucin  and  hydrochloric 
acid,  a  membrane  remains  which  is  not  cellulose.  Hartig* 
describes  a  reaction  much  like  the  foregoing  one  in  pine 
wood  attacked  by  Merulius  lachrymans,  of  which  he  says : 
' '  It  appears  as  if  there  were  a  certain  relation  between  the 
conif  erin  content  of  the  cell-wall  and  the  ease  with  which 
the  wood  is  destroyed."  This  test  is  so  delicate  that  it 
shows  the  presence  of  a  disturbing  cause  in  the  wood 
long  before  any  evidence  can  be  detected  by  the  micro- 
scope. Other  lignin  reagents  give  similar  results,  although 
not  so  striking.  Aniline  sulfate  turns  sound  wood  brilliant 
yellow,  while  it  leaves  the  affected  lamellae  almost  color- 
less. Thallin  and  phenol  give  similar  reactions.  If  the 
sections  are  treated  with  dilute  KOH  the  normal  wood 
cells  are  not  affected  beyond  very  slight  swelling.  The 
diseased  cells  swell  more  or  less,  particularly  those  parts 
which  stained  yellow  with  phloroglucin.  After  prolonged 
action  of  KOH,  the  delignified  parts  stain  blue  with  chlor- 
iodide  of  zinc.  This  indicates  that  the  first  change  in  the 


*  Hartig,  R.     Der  achte  Hausschwainm  53.     Berlin.     1885. 
12 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

cell-wall  is  the  removal  of  some  of  the  incrusting  sub- 
stances, probably  coniferin  and  vanillin.  The  KOH  re- 
moves the  remaining  substances  and  leaves  the  cellulose 
membrane  free  to  react  with  chloriodide  of  zinc.  Very 
much  rotted  wood  stains  intensely  blue  after  treatment  with 
KOH.  The  blue  color  appears  first  about  the  pits,  and 
diffuses  towards  all  sides,  looking  much  like  an  inkspot  on 
which  water  has  been  dropped,  causing  it  to  diffuse  irregu- 
larly over  the  surrounding  area.  Sound  wood  stains  yellow- 
brown  with  chloriodide  of  zinc,  even  after  treatment  with 
KOH.  With  iodine  and  sulphuric  acid,  rotted  wood  stains 
brown. 

A  very  different  form  of  disintegration  now  and  then 
occurs  (PL  4,  fig.  3).  What  the  reason  is  why  one  form 
occurs  at  one  time  and  a  second  at  some  other  time,  I  can- 
not explain.  Large  holes  appear  in  the  sound  wood,  filled 
with  a  spongy  mass  of  white  fibers.  The  holes  have  a 
white  or  tawny  lining  of  fibers,  which  can  be  pulled  off  in 
groups.  These  holes  are  as  large  as  the  ones  filled  with 
brown  powder.  The  change  in  the  wood  cells  is  almost 
exactly  like  that  found  in  pine  wood  attacked  by  Trametes 
Pini,*  above  described.  The  secondary  lamella  is  gradually 
changed  so  that  it  stains  purple  with  chloriodide  of 
zinc,  that  is,  the  lignin  substances  have  been  entirely 
removed.  Very  soon  after  the  first  signs  of  delignification 
become  evident,  the  primary  lamella  separates  into  two 
lamellae,  which  are  then  dissolved.  This  causes  the  indi- 
vidual wood  cells,  or  rather  the  cellulose  fibers,  to  fall 
apart.  No  intermediate  steps  between  the  lignified  cell- 
wall  and  the  cellulose  wall  are  to  be  detected,  which  gives 
the  impression  that  the  extraction  of  the  lignin  elements 
must  take  place  all  at  once.  The  amount  of  pure  cellulose 
fiber  thus  found  in  one  hole  is  surprising.  From  a  hole 
3-4  inches  long  several  grams  were  obtained  of  many  white 


Ilartig,  R.    Zersetzungserscheinungen,  etc.  35. 

13 


MISSOURI    BOTANICAL    GARDEN. 

fibers  without  any  impurities  whatever.  The  quantity  of 
wood  transformed  into  cellulose  is  exceeded  only,  as  far  as 
I  know,  by  that  found  in  diseased  wood  of  Juniperus, 
decayed  by  Trametes  Pini,  to  be  described  in  another 
paper. 

With  polarized  light,  the  prisms  being  crossed,  the  pri- 
mary lamella  of  sound  wood  appears  white,  i.  e.,itis 
highly  refractive ;  the  secondary  lamellae  are  darker.  The 
rotted  wood,  with  the  exception  of  some  very  minute  parti- 
cles, allows  no  light  to  pass.  The  hypothesis  of  a  crystal- 
line structure  of  the  cell-wall,  as  advocated  by  Nageli,  is 
based  largely  on  its  optical  properties.  Nageli  held  that 
the  double  refraction  indicated  a  condition  of  stress  in  more 
than  one  direction.  The  absence  of  any  refraction  in  the 
rotted  wood  indicates  a  homogeneous  condition,  i.  e.,  one 
in  which  the  stress  is  equal  in  all  directions.  The  change 
from  sound  wood  to  the  decayed  form  must  have  been  a 
profound  one  to  bring  about  this  condition.  It  has  been 
noted  for  wood  destroyed  by  Merulius  lachrymans ,*  that  it 
separates  the  white  polarized  light  into  blue  and  yellow 
parts.  Hartig  makes  no  attempt  to  explain  why  this  should 
be  so.  In  this  connection  it  may  be  said  that  rotted  wood 
of  Libocedrus  decurrens,  yet  to  be  described,  and  wood  of 
Juniperus  Viginiana  destroyed  by  Polyporus  carneus, 
appear  dark  when  viewed  with  crossed  prisms. 

HUMUS  COMPOUND. 

In  the  cells  immediately  surrounding  the  rotted  areas 
certain  parts  of  the  walls  are  colored  dark  brown  by  an 
apparently  homogeneous  substance.  This  occurs  in  various 
forms.  Most  commonly  it  has  numerous  cracks  and  fissures 
breaking  it  into  many  plates,  looking  much  like  mud  which 
has  dried  in  the  sun  (PL  4,  fig.  4),  then  again  it  appears 
in  the  form  of  irregular  granules  scattered  along  the  walls, 

*  Hartig,  R.    Der  achte  Hausschwamm  61.    Berlin.     1885. 
14 


DISEASES    OF   TAXODIUM   AXD    LIBOCEDRUS. 

usually  more  numerous  at  the  lower-end  of  the  cells.  When 
KOH  is  added  the  whole  mass  dissolves  slowly,  melt- 
ing away  like  wax;  the  tracheids  become  filled  with  the 
red-brown  solution.  By  treating  finely  divided  wood  with 
dilute  KOH  this  substance  can  be  extracted  in  quantity. 
If  the  potash  solution  is  neutralized  with  dilute  HC1,  a  red- 
brown  flocculent  gelatinous  precipitate  is  formed  slowly, 
which  gradually  settles  to  the  bottom.  When  dried  it  re- 
sumes the  appearance  seen  in  the  tracheids.  In  mass  it  is 
reddish-brown,  soft,  tasteless  and  odorless,  insoluble  in 
alcohol,  ether,  chloroform,  acetone,  turpentine,  etc.,  but 
very  soluble  in  alkalies,  KOH,  NaHPO*,  etc.,  and  can  be 
reprecipitated  from  such  solutions  by  acids.  Because  of 
its  peculiar  physical  and  chemical  properties  the  sub- 
stance is  classed  among  the  humus  compounds.  This 
humus  compound,  as  it  will  be  designated,  was  evi- 
dently at  first  in  a  liquid  condition,  as  it  fills  the  cells 
so  evenly.  Furthermore,  wherever  mycelium  occurs, 
this  is  coated  with  a  layer  of  the  compound,  so  that 
the  walls  of  the  hyphae  look  brown  and  show  several  con- 
tour-lines. Wherever  there  is  any  sign  of  decomposition, 
there  this  product  appears  immediately.  It  is  at  first  seen 
in  the  medullary  rays,  filling  the  cells  and  obscuring  their 
contents  so  that  nothing  can  be  distinguished  in  the  cells. 
The  brown  contents  of  the  rays  extend  out  through  many 
annual  rings  from  the  initial  point  of  decay.  On  several 
occasions  trees  were  found  with  exceptionally  large  quan- 
tities of  this  material.  In  these  trees  the  cavities  or  holes 
had  a  brown  powdery  mass  lying  loosely  within,  but  the 
bounding  walls  had  a  thick  coating  of  the  brown  substance. 
It  was  quite  soft,  broke  readily  with  a  shining  fracture,  was 
non-elastic  and  dissolved  readily  in  alkalies,  in  fact  agreed 
so  closely  with  substance  already  found  in  the  tracheids  as 
to  leave  no  doubt  as  to  their  being  one  and  the  same  sub- 
stance. The  finding  was  of  value  as  it  was  possible  to 
trace  the  origin  of  this  compound  directly,  which  was  not 

15 


MISSOURI   BOTANICAL    GARDEN. 

possible  in  the  majority  of  cases.  Our  present  knowledge 
of  the  humus  compounds  is  at  best  a  meager  one.  They 
are  generally  described  *  as  black  bodies,  which  form  in  the 
decay  of  organic  substances,  and  which  occur  in  soil,  peat, 
etc.  They  are  divided  f  into  three  groups  (according  to 
their  solubilities):  1.  Such  as  are  soluble  in  alcohol  and 
dilute  alkalies.  2.  Such  as  are  very  soluble  in  alkalies  and 
precipitated  by  acids  as  gelatinous  bodies  insoluble  in 
alcohol.  3.  Such  as  are  very  soluble  in  alkalies,  precipi- 
tated by  acids,  the  precipitate  soluble  in  alcohol.  The 
substance  found  in  the  cypress  wood  belongs  evidently  to 
the  second  class,  one  to  which  a  large  number  of  products 
belong,  particularly  those  obtained  from  peat  and  decaying 
vegetable  substances.  J 

Much  has  been  written  on  the  humus  compounds,  particu- 
larly those  found  in  peat.  Mulder,  §Hoppe-Seyler,  ||Griese- 
bach,H  Senft,**  Friih,t  t  have  treated  more  or  less  of  various 
compounds.  Friih  gives  the  best  general  account  and  the 
following  notes  are  taken  from  his  paper.  Me  says  (p. 
63)  :  Ulmates  and  humates,  ulmin  and  humin,  ulmic  and 
humic  acids  in  homogeneous  masses  or  in  fine  particles  give 
a  mass  which  when  moist  is  slightly  elastic.  In  drying 
these  substances  contract,  become  black,  shining  like  glass, 
hard,  and  break,  with  conchoidal  fracture.  The  splinters 


*  Beilstein,  F.    Handbuch  der  organischen  Chemie  1  :1107.     1893. 

f  Hoppe-Seyler.    Hoppe-Seyler's  Zeit.  f.  phys.  Chemie  13  : 1101. 

J  Some  of  the  humus  compound  was  sent  Dr.  Friih  who  says  of  it : 
"  It  seems  to  agree  in  its  properties  with  ulmic  acid,  or  a  calcium  salt 
of  the  same."  Dr.  Van  Bemmelen  of  Leiden  has  kindly  undertaken  to 
make  a  more  detailed  examination. 

§  Mulder,  Liebig's  Annalen  der  Chemie  (u.  Pharmacie)  36 : 343. 
1840. 

||  Hoppe-Seyler.    1.  c. 

1  Griesebach.  Uber  die  Bildung  des  Torf es  in  den  Emsmooren.  Got- 
tingen.  1846. 

**  Senft.     Die  Humus,  Marsch  und  Torfbildungen.    Leipzig.     1862. 

ft  Friih,  J.  J.  Uber  Torf  und  Dopplerit.  Zurich.  1883.  (Gives  long 
bibliography.) 

16 


DISEASES    OF   TAXODIUM    AND    LIBOCEDRUS. 

are  yellow-brown  at  the  edges,  transparent  and  soluble  in 
5%  KOH  in  the  form  of  the  acid  or  as  ulmate  or  humate; 
humin  and  ulmin  simply  swell  in  5%  KOH.  "In  the 
humification  yellow-brown  places  appear  on  the  cell  mem- 
brane, which  can  be  bleached  out  with  KOH,  in  the  form  of 
ulmin  or  humate ;  the  remaining  cell  membrane  shows  dis- 
tinct cellulose  reaction.  Lignified  membranes  ulruify  with 
difficulty,  although  wood  cells  can  change  completely  into 
peat."  Griesebach  (1.  c.)  mentions  the  transformation  of 
wood  of  Erica  Tetralix  and  Calluna  vulgaris  into  ulmin 
substances.  Humic  acids  have  been  found  in  plants,  and 
Friih  mentions  a  number  of  cases.  Thus  according  to 
Lucas,  Einhof  extracted  the  same  from  spores  of  Agaricus 
atramentarius ,  while  he  himself  obtained  one  from  Uredo 
segetum.  Friih  isolated  humic  acid  from  spores  of  Ela- 
phomyces  granulatus. 

In  the  wood  of  Taxodium  in  which  the  large  masses  of 
humus  compound  were  found  the  transition  from  lignin  to 
the  humus  bodies  was  very  evident.  PL  3,  fig.  2, 
represents  a  section  made  through  the  border  of  a  hole, 
after  staining  with  phloroglucin  and  HC1.  At  "  g  "  the 
primary  lamella  is  seen,  dark  red,  indicating  the  presence 
of  coniferin,  etc.  In  the  next  row  of  cells  the  interior  is 
coated  with  yellow-brown  masses  (h)  which  in  the  un- 
stained wood  contrast  beautifully  with  the  almost  white  cell- 
wall.  These  masses  are  found  to  be  humus  substance, 
readily  dissolved  by  dilute  KOH.  The  phloroglucin  stains 
the  secondary  lamella.  Between  this  normally  lignified 
portion  and  the  inner  humus  layer  is  a  layer  staining  yellow. 
This  is  evidently  similar  to  the  membrane  already  described 
(PI.  3,  fig.  1  ««  d  "),  i.  e.  the  wood  substance  gives  neither 
a  lignin  nor  a  cellulose  reaction.  After  treatment  with 
KOH  it  stains  deep  blue.  This  is  in  part  the  process  as 
described  by  Friih,  except  that  here  there  is  an  intervening 
step  between  the  lignin  and  the  humus  substance.  Pass- 
ing now  from  the  cells  just  described,  one  finds  the  layer 

17 


MISSOURI   BOTANICAL    GARDEN. 

of  humus  increasing  in  width  (c).  In  drying,  numerous 
fissures  have  appeared  in  the  mass.  The  lignin  layer  be- 
comes narrower  and  narrower,  then  disappears  and  at  last 
even  the  primary  lamella  no  longer  gives  the  lignin  reaction, 
and  the  whole  is  transformed  into  humus  compound  (e). 
The  positions  of  the  original  cells  are  still  very  evident, 
and  here  and  there  a  piece  (u)  of  unchanged  cell- wall  re- 
mains in  the  homogeneous  mass  of  matter. 

The  action  of  the  rotted  membranes  on  polarized  light 
has  already  been  mentioned.  The  primary  lamella  shows 
decided  light  lines  in  a  transection  of  the  kind  shown  on 
PL  3,  fig.  2,  but  as  soon  as  the  wood  no  longer  gives  the 
lignin  reaction  it  appears  dark  when  the  Mcol  prisms  are 
crossed.  The  same  is  true  of  the  humus  compound. 
Whatever  the  change  is  which  changes  a  non-homogeneous 
body  to  a  homogeneous  one,  it  is  one  which  takes  place 
when  the  chemical  structure  of  the  non-homogeneous  body 
begins  to  change.  When  a  portion  of  the  humus  mass  is 
dissolved  in  dilute  KOH  there  appear  in  the  center  of  this 
mass  certain  highly  refractive  bodies  -J- 1^  p  in  diameter, 
of  very  definite  structure  resembling  human  blood  corpus- 
cles somewhat  (PL  5,  fig.  8).  They  are  hexagonal  in 
shape  with  blunted  corners  and  have  a  much  depressed 
center,  so  that  the  edge  view  shows  four  contour  lines,  two 
parallel  lines,  and  two  of  an  hour-glass  shape.  When  exam- 
ined with  polarized  light  they  shine  brightly  when  viewed 
from  the  edge,  and  as  they  have  a  decided  Brownian 
motion,  they  alternately  flash  and  disappear.  Their  very 
variable  size,  but  constant  form,  as  well  as  their  appearance 
in  polarized  light,  suggest  that  they  are  crystals  of  some 
sort.  Hartig  *  says  that  the  comparatively  high  resistance 
of  the  walls  bounding  the  lens-shaped  pits,  is  probably  due 
to  the  large  number  of  calcium  oxalate  crystals  imbedded  in 
these  walls;  he  indicates  these  by  fine  dots  (fig.  13).  The 

*  Hartig,  R.    Der  achte  Hausschwamm  57 
18 


DISEASES    OF   TAXODIUM   AND    LIBOCEDKUS. 

small  bodies  which  he  finds  he  describes  as  "  rounded  in 
form."  He  suggests  that  they  may  be  crystalline,  and 
that  the  deposition  of  the  lime  in  the  walls  is  made  in  the 
form  of  crystals.  "If  this  be  true  it  may  be  asked 
whether  the  action  of  the  cell-wall  when  viewed  with  polar- 
ized light  may  not  be  explained  by  the  refraction  of  these 
bodies."  Hartig,  however,  did  not  prove  the  crystalline 
nature  of  the  bodies.  The  small  bodies  from  the  humus 
compound  dissolve  in  HC1,  which  might  indicate  them  to 
be  crystals  of  calcium  oxalate.  They  are  evidently  massed 
together  in  the  humus  compound,  and  become  visible  only 
when  the  latter  is  removed.  It  is  not  at  all  improbable 
that  they  were  constituents  of  the  cell-wall,  which  were  not 
destroyed  by  the  disintegrating  factor  and  remained  un- 
harmed, imbedded  in  the  liquid  mass  of  humus  compound. 
The  present  data  do  not  warrant  any  definite  conclusions 
as  to  their  real  nature  and  origin. 

From  the  description  just  given  of  the  formation  of  the 
humus  compound,  and  comparing  this  with  the  normal 
method  of  disintegration  of  the  wood,  it  seems  that  the 
process  may  be  summed  up  as  follows :  For  some  reason, 
the  normal  lignified  membrane  changes,  i.  e.,  certain  of  its 
constituents,  which  ordinarily  react  with  phloroglucin,  are 
extracted.  Then  more  profound  changes  take  place  ending 
in  the  formation  of  a  humus  compound.  This  ordinarily 
diffuses  through  the  adjoining  cells,  and  ultimately  hardens 
in  the  tracheids  surrounding  the  rotted  area  and  in  the  medul- 
lary rays .  At  the  same  time  all  contents  of  the  cells,  hyphae, 
starch  grains,  etc. ,  are  covered.  Numerous  experiments  were 
made  to  determine  the  approximate  per  cent,  of  matter  solu- 
ble in  dilute  KOH,  both  in  much  rotted  wood  and  in  wood 
immediately  surrounding  the  holes,  apparently  sound.  The 
amounts  were  found  to  vary  between  wide  limits.  On  an 
average  about  34%  was  obtained  from  much  rotted  wood, 
the  remaining  66%  consisting  of  pieces  of  wood  fibres 
not  transformed.  In  the  wood  immediately  surrounding 

19 


MISSOURI   BOTANICAL    GARDEN. 

the  holes  6-8%  was  obtained.  The  soluble  matter  was 
precipitated  from  the  2%  KOH  solution  with  dilute  HC1 
and  dried  at  100°  C. 


WOOD  BETWEEN  THE  ROTTED  AREAS. 

The  wood  between  the  holes  is  darker  in  color  than 
the  normal  wood,  but  cannot  be  distinguished  from  it 
structurally.  Numerous  fungus  threads  pass  through  the 
walls  or  have  punctured  them  in  many  places.  Near  the 
holes  much  of  the  humus  compound  occurs,  and  many  of 
the  pits  show  the  peculiar  arrangement  of  oil  globules. 
The  specific  grayity  of  sound  heart  wood  and  that  of  the 
wood  between  the  holes,  was  determined  by  weighing 
blocks  and  measuring  them.  As  the  plates  of  wood 
between  the  holes  as  a  rule  are  but  -J-J  inch  wide,  and 
the  mass  of  wood  not  occupied  by  holes  but  ^  inch  long, 
the  pieces  to  be  measured  had  to  be  rather  small.  To 
bring  the  two  tests  under  similar  conditions,  the  blocks 
from  normal  wood  were  made  of  similar  size.  The  blocks 
were  dried  at  100°  C.  until  approximately  constant  weight 
was  reached.  The  specific  gravity  of  sound  wood  was 
found  to  be  .508;  that  of  the  other,  .401.  These  figures 
are  probably  only  relatively  correct,  but  as  each  is  the 
average  of  a  number  of  blocks,  they  seem  to  show  that 
even  if  no  visible  change  has  taken  place  in  the  wood 
between  the  holes,  some  change  must  have  occurred, 
otherwise  there  would  not  have  been  so  great  a  difference 
in  specific  gravity.  Very  pecky  cypress  planks  which  had 
been  exposed  in  lumber  yards  for  many  years,  were  exam- 
ined. The  powder  and  wood  fibers  which  had  filled  the 
holes  had  been  washed  out  and  had  left  a  smooth,  even 
surface.  The  wood  was  to  all  intents  and  purposes  very 
sound,  and  no  change  except  numerous  perforations  in  the 
walls,  and  the  presence  of  much  humus  compound,  could 
be  detected. 
20 


DISEASES    OF    TAXODIUM    AXD   LIBOCEDRUS. 

It  is  this  property  of  the  pecky  cypress  not  to  pass  be- 
yond a  certain  stage  of  decay,  which  has  made  it  possible  for 
the  wood  to  be  utilized  in  a  variety  of  ways.  Dickeson  & 
Brown  call  attention  to  this  fact :  ' '  There  is  this  peculiarity 
of  this  disease,  that  the  cutting  down  of  the  timber  arrests  its 
further  progress,  and  timber  thus  affected,  although  not  as 
strong,  is  found  to  last  as  long  as  that  which  is  very  sound." 
This  is  probably  a  unique  case  of  specifically  "  rotten  " 
wood  still  capable  of  being  used  for  commercial  purposes. 
The  durability  of  cypress  timber  is  universally  admitted, 
and  pecky  cypress  does  not  seem  to  be  much  less  so. 
Where  it  is,  as  in  this  case,  a  question  of  dollars  and  cents, 
the  testimony  of  practical  lumbermen  is  especially  valuable. 
Thus,  whereas  sound  cypress  lumber  sells  for  $20-$ 2 5  per 
1,000  ft.  B.M.,  pecky  cypress  sells  for  $5-$10  per  1,000 
ft.  B.M. ;  generally  from  $5-$ 8.  One  firm  makes  two 
grades  of  pecky  planks:  "pecky,"  and  "dangerously 
pecky;  "  "  the  latter  means  that  the  holes  are  so  large 
that  a  mule  might  put  his  foot  through  "  !  Mr.  G.  M. 
Bowie,  of  Whitecastle,  La.,  writes:  "  I  am  watching  some 
pecky  planks  laid  on  the  ground,  exposed  to  rain  and  sun; 
they  are  unchanged  so  far  in  ten  years."  Throughout  the 
Southern  States  pecky  cypress  boards  are  used  for  bridge 
planking  on  plantations,  for  siding,  sidewalks,  flooring, 
culverts,  foundations  under  brick  work,  in  wet  places,  etc. 
Mr.  A.  S.  Mohr,  of  Apalachicola,  Fla.,  says:  "  We  use 
pecky  planks  2  in.  thick  and  upwards  for  making  drive- 
ways, wharfs,  tramways,  and  for  such  purposes  it  is  in- 
valuable." 

In  Mobile,  for  instance,  where  there  are  open  ditches  along 
many  streets,  the  vertical  bank,  flanking  the  pavement, 
and  the  bottom  of  the  ditch  are  lined  with  pecky  boards, 
and  their  lasting  powers  seem  to  be  fully  equal  to  sound 
boards.  (PI.  6.) 

For  sidewalks,  such  lumber  is  used  in  almost  every  town 
or  city  within  the  reach  of  cypress  swamps,  arid  when  the 

21 


MISSOURI   BOTANICAL    GARDEN. 

softer  powder  has  worn  away  the  grooved  boards  have  a 
singular  appearance. 

From  such  data  it  may  safely  be  said  that  the  disintegra- 
tion never  goes  beyond  a  certain  stage.  When  a  tree  is 
cut  down  the  further  progress  of  the  disease  is  stopped. 
No  tree,  as  far  as  is  known,  has  been  seen  in  which  all  the 
wood  had  been  destroyed,  and  it  is  for  this  reason  that  a 
diseased  tree  remains  standing  even  when  much  decayed. 

STRENGTH  OF  CYPRESS  WOOD. 

A  number  of  tests  were  made  to  determine  the  relative 
crushing  strength  of  sound  cypress  wood  and  that  of  very 
pecky  wood.*  In  making  these  tests  blocks  cut  from  the 
heartwood  were  used.  These  were  dried  in  a  kiln  for  three 
days  and  were  tested  immediately  after  being  taken  from 
the  drying  oven.  The  tests  were  made  with  the  machinery 
used  for  the  timber  tests  of  the  U.  S.  Division  of  Forestry,  f 
A  full  description  of  the  same  will  be  found  in  the  bulletin 
referred  to. 


CRUSHING  STRENGTH  (ENDWISE),  OF  SOUND  CYPRESS.     (HEARTWOOD,) 


1 

Dimen- 
sions of 
block. 
Inches. 

Height. 
Inches. 

Area. 
Square 
inches. 

Breaking 
load. 
Pounds. 

Breaking 
load  per 
square 
inch. 
Pounds. 

Locality. 

1 

1.32X1-30 

3.24 

1.71 

12,300 

7,191 

From  Lutcher,  La. 

2 

1.69XL27 

3.23 

2.14 

15,490 

7,144 

((                      U                  11 

3 

1.55X1.29 

3.00 

1.99 

14,250 

7,160 

((               «(            (( 

*  In  making  these  tests  I  am  much  indebted  to  Mr.  W.  H.  Henby  for 
material  assistance. 

t  Timber   physics.    Pt.    I.    (Bull.  U.   S.   Div,   of    Forestry    6:  31.) 
Washington.     1892. 
22 


DISEASES    OF   TAXODIUM   AXD    LIBOCEDEUS. 


CRUSHING  STRENGTH  (ENDWISE),  OF  PECKY  CYPRESS.     (HEARTWOOD.) 


Breaking 

1 

Dimen- 
sions. 
Inches. 

Height. 
Inches. 

Area. 
Sq. 
inches 

Breaking 
load. 
Pounds. 

load  per 
square 
inch. 

Character. 

Pounds. 

A  little  sapwood 

1 

2.13X3.25 

5.98 

7.14 

35,170 

4,925 

in  one  corner.   Up- 
per surface  showed 

4  pecky  spots. 

Near     center    of 

2 

2.65X3.17 

6.87 

8.40 

43,680 

5,200 

tree,  14  holes  visible 

on  upper  surface. 

Very  pecky.    14-18 

3 

2.92X3.16 

6.86 

9.23 

40,130 

4,350 

holes  visible  on  up- 
per and  lower  sur- 

faces. 

4 

3.25X3.37 

6.55 

10.95 

56,050 

5,120 

Very  pecky.  Same 
appearance  as  No.  3. 

5 

3.47X3.52 

7.75 

12.21 

40,850 

3,345 

Extremely  pecky. 

1 


CRUSHING  STRENGTH  (ENDWISE),  OF  PECKY  CYPRESS   BEFORE 
DRYING.    (HEARTWOOD.) 


c 

& 

Dimen- 
sions. 
Inches. 

Height. 
Inches. 

Area. 
Sq. 
inches 

Breaking 
load. 
Pounds. 

Breaking 
load  per 
sq.  inch. 
Pounds. 

Weight 
moist. 
Grams. 

Weight 
dry. 
Grams. 

% 

Moist- 
ure. 

1 

3.03X3.22 

4.37 

9.75 

30,200 

3,097 

335 

278 

17.0 

2 

3.30X3.44 

3.06 

11.35 

35,680 

3,143 

275 

'  238 

13.6 

3 

3.51X3.55 

3.29 

12.46 

35,970 

2,886 

287 

261 

9.0 

In  these  tables  but  a  few  tests  are  given :  a  more  exten- 
sive list  is  in  preparation.  A  glance  at  these  tables  will 
show  how  comparatively  strong  the  very  pecky  wood  is, 
which  is  a  rather  surprising  feature.  It  is  of  course  diffi- 

23 


MISSOURI   BOTANICAL    GARDEN. 

cult  to  state  exactly  how  pecky  a  certain  piece  is,  but  the 
samples  tested  were  considered  as  fair  averages  of  the  grade 
generally  used  for  sidewalks,  etc.  The  block  marked  5 
was  very  much  more  pecky  than  the  others.  From  the 
third  table  it  appears  that  when  wet  the  wood  is  less  strong 
than  when  thoroughly  dry,  which  is  true  of  all  woods. 
The  breaking  of  the  pecky  blocks  was  almost  without  ref- 
erence to  the  holes.  The  wood  between  the  holes  had  to 
stand  the  load,  and  that  it  was  capable  of  holding  up  as 
much  as  it  did  is  another  proof  of  its  comparative  sound- 
ness. The  number  of  tests  made  so  far  is  as  yet  too  small 
to  determine  whether  any  relation  exists  between  the  abso- 
lute weight  of  wood  fiber  present  in  the  pecky  logs  and  the 
breaking  strength. 

MYCELIUM. 

Within  the  holes,  and  throughout  the  heartwood  of  a  dis- 
eased tree,  the  mycelium  of  some  fungus  is  constantly  met 
with.  This  is  present  but  sparingly,  and  rarely  forms  ex- 
tended masses  or  felts.  In  spite  of  extensive  and  search- 
ing examinations  of  a  very  large  number  of  cypress  trees 
for  several  years,  no  fruiting  organ  has  yet  been  met  with. 
The  only  fungus  ever  reported  was  the  one  mentioned  by 
Sargent  *  which,  as  far  as  can  be  determined  now,  had 
little  adequate  foundation.  Of  the  other  fungi  hitherto 
reported  as  growing  on  Taxodium  none  could  be  brought 
into  any  causal  connection  with  the  mycelium  always  found 
in  the  tree.  It  is  to  be  hoped  that  before  long  the  fruiting 
form  may  be  discovered. 

The  disintegration  of  the  wood  is,  in  many  respects,  like 
that  brought  about  by  Trametes  Pini,  but  so  far  there  is 
no  evidence  to  prove  that  this  is  the  fungus  which  causes 
the  "  peckiness." 

Wherever  there  is  any  sign  of  decay  in  the  cypress  wood, 

*  Sargent,  C.  S.    Forest  trees  of  N.  A.    10th  Census  9  : 184. 
24 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

a  distinct  mycelium  is  present,  and  the  probabilities  are 
strong  that  it  is  the  one  which  brings  about  the  decay  of 
the  wood.  The  hyphae  are  brownish  when  young,  but 
soon  become  colorless .  Their  chief  and  striking  characteristic 
is  the  presence  of  very  many  clamp  connections  (PL  5,  fig. 
1).  Brefeld,*  Hartig,f  and  others  have  shown  that  these 
organs  are  to  be  found  among  the  Basidiomycetes,  particu- 
larly among  the  Agaricineae  and  Polyporei.  Brefeld  (I.e.) 
describes  their  formation  in  Coprinus  stercorarius  as  lateral 
outgrowths  of  one  cell  fusing  with  the  cell  beneath  it,  and 
then  forming  a  separating  wall.  At  such  points  numerous 
branches  usually  appeared.  Hartig  (1.  c.)  describes  the 
clamp  connections  of  Merulius  lachrymans.  In  this  fungus 
they  bud  out,  and  form  a  branch,  sometimes  before  the 
separating  wall  in  the  clamp  has  fused  with  the  next  cell. 
This  is  a  unique  case  among  the  Hymenomycetes,  as  the 
clamps  are  "  sterile  "  in  all  other  forms. 

The  clamp  connections  occur  on  all  parts  of  the  mycelium 
found  in  Taxodium,  but  in  no  case  did  any  of  them  branch 
as  they  do  in  Merulius.  The  mycelium  consists  of  large 
hyphae  with  distinct  thin  walls,  and  hyphae  of  smaller  diame- 
ter. The  larger  hyphae  are  constricted  at  the  points  where 
two  cells  join.  They  branch  frequently,  giving  rise  to  the 
hyphae  of  smaller  diameter.  These  in  turn  branch  and 
rebranch.  At  certain  points  a  short  branch  is  given  off. 
which  divides  very  rapidly  into  the  finest  threads,  of  hair- 
like  dimensions.  These  smaller  hyphae  penetrate  the  cell- 
walls  in  all  directions.  Connections  between  adjacent 
hyphae  occur  frequently,  also  complicated  masses,  where 
large  numbers  of  hyphae  have  fused  more  or  less.  As  a 
rule  there  is  but  very  little  mycelium  to  be  found  either 
in  the  much  rotted  wood  or  the  intermediate  parts.  Nu- 
merous holes  occur  all  through  the  wood,  indicating  where 


*  Brefeld,   O.    Untersuchungen  iiber  Schimmelpilze  3 : 16.     1877. 
f  Hartig,  R.     Der  achte  Hausschwamm  14.    pi.  l,fig.  3. 

25 


MISSOURI   BOTANICAL   GARDEN. 

the  hyphae  had  passed  through  the  walls.  The  threads 
show  no  preference  for  the  pits.  The  holes  often  have  the 
shape  of  a  figure  8,  i.  e.  they  enlarge  within  the  secondary 
lamella,  a  feature  which  is  common  to  wood  destroyed  by 
many  wood-destroying  fungi.  The  scarcity  of  mycelium  is 
striking,  resembling  in  this  respect  wood  in  which  Poly- 
porus  sulphureus  has  been  growing.*  In  branches  where 
the  disease  is  in  its  youngest  stage,  the  mycelium  occurs 
more  plentifully  in  those  areas,  which  correspond  to  the 
holes  to  be  formed  later  on.  Between  these  areas  the 
hyphae  pass,  boring  through  the  tangential  walls. 

Besides  the  colorless  mycelium,  a  mycelium  is  often 
present  in  the  wood  between  the  decayed  holes.  This 
appears  to  belong  to  some  saprophyte,  which  has  nothing 
to  do  with  the  original  decomposition.  This  mycelium  is 
composed  of  brown  threads  which  pass  through  the  tan- 
gential walls  preferably  and  follow  the  direction  of  the 
tracheids  up  and  down.  These  hyphae  form  marked  at- 
tachment organs  when  boring  through  the  cell-walls.  Frankf 
described  such  organs  as  formed  by  the  germ  tubes  of  Fusi- 
cladium  tremulae.  The  hypha  when  it  touches  the  epidermis 
forms  a  swelling  with  one  or  more  pores,  from  which  fine 
tubes  push  through  the  walls  into  the  epidermal  cells.  He 
called  the  swollen  parts  "  Appressorien  "  or  attachment 
organs,  and  believed  that  they  aided  the  hypha  in  punctur- 
ing the  wall.  De  Bary  J  found  similar  organs  in  germ  tubes 
of  Peziza  Sderotiorum ;  these  were  formed  * '  owing  to  a 
mechanical  stimulus,  which  the  resistance  of  a  solid  body 
exerts  on  the  hyphal  branches."  Biisgen  §  described  the 

*  Hartig,  R.    Zersetzungserscheirmngen  des  Holzes  110. 

f  Frank,  B.  Uber  einige  neue  u.  weniger  bekannte  Pflanzenkrank- 
heiten.  (Ber.  d.  deut.  bot.  Ges.  1 : 30.  1883.) 

%  De  Bary,  A.  Uber  einige  Sclerotinien  u.  Sclerotienkrankheiten. 
(Bot.  Zeit.  44:377.  1886.) 

§  Biisgen,  M.    Uber  einige  Eigenschaf  ten  der  Keimlinge  parasitische 
Pilze.     (Bot.  Zg.  51 :  53.     1893.) 
26 


DISEASES    OF   TAXODIUM    AND    LIBQCEDRUS. 

attachment  organs  as  smaller  portions  of  a  hypha,  formed 
as  a  result  of  contact  or  pressure  irritation.  "  These 
organs  adhere  very  closely  to  the  cell- walls  and  in  that  way 
probably  act  as  braces  to  give  the  penetrating  hypha  an 
opportunity  to  exert  the  mechanical  pressure  necessary  to 
penetrate  the  cell- wall."  Miyoshi  *  found  that  in  order  to 
penetrate  a  wall  "  the  fixation  of  the  hypha  was  absolutely 
essential ' '  and  explains  the  formation  of  attachment  organs 
as  tending  in  that  direction.  Hartig  f  figures  several  cases 
of  swollen  hyphae  in  the  mycelium  of  Polyporus  vapo- 
rarius. 

The  penetration  of  the  cell-wall  is  brought  about,  accord- 
ing to  Brefeld,^  Biisgen  (1.  c.),  Miyoshi  (1.  c.),  Ward,  § 
and  others  by  the  chemical  action  of  a  ferment  given  off  by 
the  tip  of  the  hypha,  aided  by  pressure.  In  the  diseased 
wood  of  Taxodium  the  brown  hyphae  pass  through  the 
cell-walls  of  the  wood  fibers  of  both  spring  and  summer 
wood  in  a  radial  direction.  The  path  of  a  hypha  is  made 
up  of  a  succession  of  short  curves,  each  within  the  lumen 
of  a  wood  cell  (PL  4,  fig.  1).  When  the  tip  of  a  hypha 
touches  the  wall  it  is  deflected  considerably,  as  if  the  hypha 
were  pressing  against  the  wall  and  pushing  along  the  same. 
At  the  same  time  the  tip  swells,  and  a  thread  of  much 
smaller  diameter  pushes  into  the  wall.  Sometimes  there 
may  be  two  such  threads  (PI.  5,  fig.  9).  When  they 
have  passed  through  the  wall  they  enlarge  to  the  former 
size  of  the  hypha,  and  grow  on  through  the  next  cell,  to 
be  deflected  as  before  upon  reaching  the  opposite  wall. 
On  PL  5,  fig.  9,  a  number  of  these  attachment  organs  are 
represented,  occurring  in  the  wood  of  Taxodium,  and  also 

*  Miyoshi,  Manabu.  Die  Durchbohrung  von  Membranen  durch 
Pilzfaden.  (Prings.,  Jahrb.  f.  wiss.  Bot.  28:269.  1895).— Uber  Che- 
motropismus  der  Pilze.  (Bot.  Zg.  52  : 1.  1894.) 

t  Hartig,  R.     Zersetzungserscheinungen,  etc.  pi.  8.  fig.  11. 

J  Brefeld,  O.     Untersuchungen  tiber  Schimmelpilze  4 : 112.  /.  11, 15. 

§  Marshall-Ward,  H.    On  a  lily  disease.    (Ann.  Botany  2 :  319.    1889.) 

27 


MISSOURI    BOTANICAL    GARDEN. 

in  diseased  wood  of  Libocedrus  decurrens.  At  a  one  of 
the  attachment  organs  has  formed  a  branch.  These  organs 
adhere  very  firmly  to  the  walls  against  which  they  are 
pressed ;  from  the  curved  form  of  the  hypha  one  is  led  to 
suppose  that  the  pressure  exerted  by  the  hypha  must  be 
considerable.  The  reason  for  supposing  these  brown 
hyphae  to  be  saprophytic  is  that  they  are  usually  found 
somewhere  in  the  wood  near  a  knot  hole,  where  there  is 
abundant  opportunity  for  the  entrance  of  saprophytes. 

In  many  cases  a  form  of  mycelium  with  very  thick  walls 
occurs.  This  has  few  clamp  connections  and  forms  thick 
felts  in  the  holes.  This  was  found  only  in  logs  after  they 
had  been  cut,  so  there  is  some  reason  for  considering  it  as 
foreign  to  the  disease.  The  great  age  of  many  of  the  cypress 
trees,  and  the  consequent  presence  of  numerous  places  where 
branches  have  been  broken  off,  allows  many  fungi  to  get  in 
which  live  on  the  dead  and  decaying  wood,  but  which  seem  to 
have  nothing  to  do  with  the  peckiness.  Their  presence  makes 
the  study  a  difficult  one  at  times,  especially  as  they  seem  to 
grow  rapidly  and  fructify  readily .  Thus  a  number  of  spore 
forms  were  met  with,  but  in  no  case  could  these  be  brought 
into  any  connection  with  the  colorless  mycelium.  One 
form  was  found  very  often  (PI.  5,  fig.  5)  also  frequently 
present  in  diseased  wood  of  Libocedrus  decurrens  and  Juni- 
perus  Virginiana.  The  spores  are  almost  round,  about 
1  p.  in  diameter,  brown,  with  a  distinct  wall  and  a  central 
shining  body  which  is  not  affected  by  reagents.  Many  of 
the  spores  have  short  knobs.  The  spores  occur  in  such 
numbers  in  the  wood  around  the  holes  that  it  seems  proba- 
ble that  they  were  formed  in  chains  and  may  be  considered 
chlamydospores.  A  number  of  times  chains  of  two  or 
three  were  found  with  fine  remnants  of  hyphae  attached. 
These  spores  were  placed  in  cultures  of  dung,  cypress  agar, 
and  gelatin,  but  have  so  far  refused  to  germinate.  It  is 
possible  that  they  represent  some  form  of  entophytic 
organism  (Chytridiaceae  9  Phytomyxae?)  studied  by 
28 


DISEASES    OF    TAXQDIUM    AND    LIBOCEDRUS. 

Fischer,  Dangeard,  De  Wildeman  and  others.  Brefeld  * 
records  an  instance  of  similar  spores  in  Peziza  tube- 
rosa.  These  were  constricted  off  in  chains  and  refused 
to  germinate.  Hartig  t  found  spores  in  wood  destroyed  by 
Polyporus  sulphureus.  These,  he  says,  belong  to  some 
saprophytic  fungus,  always  found  with  Polyporus  sulphur- 
eus. In  wood  of  Quercus  alba  and  Q.  nigra  destroyed  by 
Polyporus  sulphureus,  collected  in  New  York  and  Arkansas, 
similar  spores  were  found,  represented  on  PL  5,  fig.  8,  for 
comparison.  They  seem  to  be  constantly  present  wherever 
Polyporus  sulphureus  has  destroyed  oak  wood.  The  asso- 
ciation of  these  two  fungi  is  not  understood  as  yet,  and 
awaits  further  investigation. 

Besides  the  brown  spores  a  number  of  others  occur,  a 
few  of  which  may  be  mentioned.  One  form,  large,  black 
spores  in  chains,  resembles  Willkomm's  J  Xenodochus  ligni- 
perda  (PI.  5,  fig.  7).  Another  form,  consisting  of  large 
two-celled  chlamydospores  (PI.  5,  fig.  4),  is  not  infre- 
quent. 

PROGRESS  OF  THE  DISEASE. 

In  the  early  stages  of  the  disease  the  wood  turns  yellow 
in  localized  areas,  about  \  inch  wide  and  extending  longi- 
tudinally with  the  wood  fibers  for  several  inches  (PL  1, 
fig.  1).  These  areas  are  separated  by  intervening  layers 
of  wood,  unchanged  in  color.  In  the  wood  cells  of  the 
yellow  areas  numerous  hyphae  of  the  colorless  mycelium 
are  found.  The  larger  hyphae  extend  longitudinally 
through  the  cells  and  give  off  many  branches  which  pass 
and  repass  through  the  walls.  The  ultimate  hair  like 
branches  reach  every  cell  in  the  area.  Numerous  clamp 
connections  are  to  be  seen.  Between  the  yellow  areas  the 
hyphae  extend  through  the  wood  cells,  passing  through  the 

*  Brefeld,  0.     Bot.  Untersuchungen  liber  Schimmelpilze  4 :  113. 
t  Hartig,  K.    Zersetzungserscheimmgen,  etc.  113.    pi.  14.  f.  10-12. 
%  Willkomm,  M.    Die  mikroscopischen  Feinde  des  Waldes.    pi.  II. 
f.  S.     1866. 

29 


MISSOURI   BOTANICAL    GARDEN. 

walls  radially  to  another  yellow  area  at  that  height  or  longi- 
tudinally to  one  above.  Immediately  around  the  yellow 
areas  it  looks  as  if  the  hyphae  were  passing  through  this 
wood  as  rapidly  as  possible.  As  the  disease  progresses  the 
mycelium  can  be  found  only  sparingly  in  the  yellow  areas 
and  in  the  surrounding  wood.  Their  former  presence  is 
indicated  by  the  numerous  holes  in  the  walls. 

From  the  facts  presented,  it  seems  that  the  growth  of 
the  fungus  is  about  as  follows :  The  mycelium  starts  at 
some  point  in  the  heart- wood  where  it  flourishes  in  a  limited 
area  for  some  time.  Some  of  the  threads  then  grow  out 
from  this  area  (which  is  limited,  for  some  reason  or  other), 
and  grow  both  transversely  and  longitudinally  from  the 
original  center.  At  points  some  distance  from  this  center 
new  centers  are  established,  which  in  time  are  limited 
and  form  starting-points  for  further  growth.  One  may 
cut  through  a  young  branch  and  find  the  cut  surface  per- 
fectly sound.  On  splitting  both  pieces  of  the  branch,  one 
may  find  that  at  points  several  inches  above  the  cut  one  or 
more  distinct  yellow  areas  are  present,  and  the  same  may 
be  true  of  the  piece  below  the  cut.  In  the  wood  between, 
numerous  hyphae  occur,  which,  however,  do  not  spread  in 
this  wood.  The  areas  where  vigorous  development  has 
taken  place  ultimately  become  holes,  and  the  tree  then 
appears  as  already  described,  i.  e.,  sound  wood  filled 
with  lens-shaped  cavities.  The  original  hyphae  are  gradu- 
ally absorbed,  so  that  after  a  time  the  figure-8  holes  in  the 
walls  are  the  only  evidence  of  their  former  presence. 

The  path  of  the  mycelium  is  always  the  shortest  distance 
from  hole  to  h«ole.  This  apparent  avoidance  of  the  wood 
between  holes  —  an  apparent  preservation  —  is  very  strik- 
ing. It  is  suggested  that  this  is  probably  due  to  chemical 
influences  which  affect  the  hyphae  in  this  manner.  All 
attempts  to  grow  the  mycelium  have  so  far  failed.  Media 
were  prepared  from  decoctions  of  cypress  wood  and  care- 
fully titrated ;  they  were  then  inoculated  with  fresh  myce- 
30 


DISEASES   OF   TAXODIUM   AND   LIBOCEDRU8. 

Hum,  which,  however,  did  not  grow.  Fresh  pecky  wood 
has  been  kept  in  moist  chambers  now  for  almost  three 
years  without  any  sign  of  growth.  Further  experiments 
are  in  progress. 

PROPAGATION  OF  DISEASE. 

The  constant  presence  of  the  colorless  mycelium  in  dis- 
eased trees  makes  it  seem  probable  that  this  is  the  vegetative 
part  of  a  fungus  which  causes  the  decay.  As  has  been 
said,  no  fruiting  organ  has  yet  been  found,  so  the  manner 
in  which  this  disease  is  carried  from  tree  to  tree  is  still  to 
be  discovered.  A  large  number  of  logs  were  split  open, 
and  in  some  of  these,  large  places  were  occasionally  met  with 
where  an  old  branch  had  been  healed  over,  leaving  a  cavity. 
In  this  cavity  dense  white  felts  of  the  mycelium,  in  which 
numerous  crystals  of  calcium  oxalate  were  imbedded,  were 
obtained.  There  was,  however,  no  sign  of  a  fruiting 
organ.  In  some  boards  beginnings  of  such  felts  were  found 
but  none  of  these  have  developed  any  further.  Reasoning 
by  analogy  from  the  diseases  of  trees  already  known  we 
ought  to  find  at  some  time  a  pileus  of  some  sort.  That 
infection  takes  place  through  a  broken  branch  or  some 
part  of  the  top  of  the  tree  is  most  probable.  Many  trees 
were  cut  down  in  which  the  "peck"'  could  be  traced 
directly  to  a  broken  branch,  extending  up  and  down  from 
this  point.  This  was  especially  marked  where,  as  in  a 
number  of  instances,  the  "  peck  "  was  confined  to  one  side 
of  a  tree. 

LOCALIZATION  OF  DISEASE. 

The  most  characteristic  feature  in  connection  with  this 
disease,  distinguishing  it  from  others  so  far  described,  is 
its  peculiar  localization,  i.  e.,  the  destruction  of  the  wood 
in  distinctly  localized  areas.  The  formation  of  the  holes 
has  been  described,  and  it  has  been  noted  that  the  contrast 
between  diseased  areas  and  sound  wood  is  a  marked  one, 

31 


MISSOURI   BOTANICAL    GARDEN. 

furthermore  that  fungus  threads  occur  all  through  a  given 
section  of  a  tree. 

The  manner  in  which  fungi  influence  their  hosts  varies 
considerably.  One  may  consider  the  distribution  of  the 
mycelium  within  the  host.  There  are  but  few  references 
to  this  point  in  discussions  on  fungi.  Tubeuf  *  says  : 
"  A  large  number  of  fungi  have  a  mycelium  which  never 
extends  beyond  a  very  short  distance  round  the  point  of  first 
infection,  and  cause  only  local  disease,  frequently  with  no 
perceptible  disturbing  effect  on  the  host.  Such  is  the  case 
with  leaf  spot  diseases."  Thus  Frank  f  describes  the 
mycelium  of  Gloeosporium  Lindemuthianum  as  caus- 
ing a  browning  of  the  tissues  as  far  as  the  mycelium 
extends.  The  same  is  true  of  Cercospora.  The  mycelium 
of  Aecidium  Rhamni  on  Rhamnus  frangula  has  a 
local  distribution, J  so  also  that  of  many  Erysipheae, 
for  instance  Microsphaera  densissima  also  Uncinula  necator 
of  which  an  interesting  case  was  recently  described  by 
Stevens.  §  This  localization  of  the  mycelium  may  be  due 
to  mechanical  obstructions,  such  as  the  veins  of  a  leaf,  as  in 
Puccinia  Podophylli,  or  to  chemical  reaction  on  the  part 
of  the  host.  The  large  majority  of  fungi  have  a  mycelium 
which  extends  through  large  areas  of  their  hosts.  Wakker 
(1.  c.)  classifies  parasitic  fungi  according  to  their  effects  on 
their  hosts  as  producing  either  mechanical  or  chemical 
effects.  By  mechanical  effects  he  understands  such  as  are 
due  to  direct  pressure.  The  vast  majority  affect  their 
hosts  chemically.  Here  again  two  classes  may  be  distin- 
guished, such  as  produce  chemical  effects  '«  which  will  im- 
mediately, or  otherwise  exert  a  direct  destructive  influence 

*  Tubeuf,  C.  Freiherr  von.    Diseases  of  plants  16.     (Eng.  edit.) 

t  Frank,  B.  Uber  einige  neue  u.  weniger  bekannte  Pflanzenkrank- 
heiten.  (Ber.  d.  deut.  bot.  Ges.  1 : 31.  1883.) 

J  Wakker,  J.  H.  Untersuchungen  tiber  den  Einfluss  parasitischer 
Pilze  auf  ihre  Nahrpflanzen.  (Prings.,  Jahrb.  f .  w.  Bot.  24  :  505.  1892.) 

§  Stevens,  F.  L.  A  peculiar  case  of  spore  distribution.  (Bot,  Gaz. 
27  :  138.  1899.) 

32 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRU8. 

on  their  hosts  and  those  which  live  for  a  longer  or  shorter 
period  with  their  host  without  producing  such  effect."* 
To  the  first  class  belong  all  such  plants  as  produce  imme- 
diate death,  like  Peronospora,  Agaricus  melleus  and  many 
Polyporei,  and  those  producing  hypertrophies,  such  as 
Gymnosporangium,  Exoascus,  and  others.  To  the  second 
class  belong  many  Uredineaesaid  Ustilagineae,Exobasidium> 
etc.  In  the  latter  cases  the  mycelium  may  live  for  a  long 
period  in  the  cells  without  any  perceptible  effect  on  them. 
The  reason  for  this  "conservation"  (Tubeuf,  1.  c.)  is 
doubtless  to  be  sought  in  complex  chemical  conditions  which 
bring  about  one  kind  of  effect  with  one,  and  another  with  a 
different  fungus. 

In  all  the  cases  just  mentioned,  one  is  dealing  with  living 
tissues  capable  of  reaction  of  some  sort.  This  reaction 
may  take  the  form  of  starch  accumulation,  hypertrophied 
structures  or  the  formation  of  products  antagonistic  to  the 
growth  of  the  invading  fungus.  The  bacteria  are  a  good 
example  of  organisms  bringing  about  the  last  form  of  reac- 
tion, i.  e.,  where  the  host  produces  substances  which 
neutralize  the  poisonous  products  formed  by  the  parasite. 
To  what  extent  similar  processes  take  place  in  plant  cells  is 
yet  unknown,  but  there  seems  to  be  no  reason  why  they 
should  not. 

In  the  heartwood  of  a  tree  one  is  dealing  with  a  plant 
member  to  all  intents  and  purposes  dead,  i.  e.,  its  power  to 
react  to  any  stimulus  has  been  lost,  so  that  such  influences 
as  would  affect  the  distribution  as  well  as  chemical  activi- 
ties of  a  mycelium  in  a  living  member  can  have  no  bearing 
here.  There  is  in  the  Taxodium  a  marked  localization, 
and,  as  will  be  shown,  this  is  also  present  in  Libocedrus 
decurrens,  Juniperus  Virginiana,  J.  Bermudiensis,  and  to 
some  extent  in  pines  attacked  by  several  of  the  Polyporei. 

The  localization  of  chemical  action,  for  such  the  disinte- 


*  Tubeuf,  C.  Freiherr  von.    Diseases  of  plants  21. 

33 


MISSOURI   BOTANICAL    GARDEN. 

grating  action  on  wood  must  be,  cannot  be  due  to  mechan- 
ical causes,  such  as  difference  in  the  character  of  the  wood 
cells,  or  the  presence  of  obstructing  layers.  In  the  first 
place  all  wood  cells  are  disintegrated,  whether  they  be  of 
the  spring  or  summer  wood,  and  the  bounding  lines  of  a 
cavity  are  not  influenced  by  the  harder  summer  wood  as 
might  be  supposed.  Then  again  no  resistant  layers,  as 
such,  excepting  the  harder  summer  wood,  exist  in  the  heart- 
wood.  The  isolated  resin  cells  seem  to  have  no  bearing  in 
this  connection.  The  only  remaining  explanation  is  to 
attribute  the  local  decay  to  chemical  influences,  which  pre- 
vent the  decay  from  spreading  beyond  well-defined  limits. 
It  is  a  well-known  fact  that  certain  kinds  of  wood  are 
more  durable,  i.  e.,  resist  the  destructive  influences  of  fungi 
longer  than  others.  Willows,  for  instance,  are  more 
easily  destroyed  than  oaks  or  cedar.  Frank  *  and  Temme  f 
have  shown  that  in  dicotyledonous  trees  a  certain  preserv- 
ative gum  is  found.  This  is  formed  in  all  wounds  open 
to  the  air,  and  occurs  normally  in  all  heartwood.  This 
wound  gum  fills  the  vessels  similarly  to  thylloses,  and  ren- 
ders them  impassable  to  air  and  water.  The  wound  gum 
is  insoluble  in  alcohol,  ether,  H2SO4,  KOH,  but  soluble  in 
hot  HNOs.  These  authors  do  not  explain  what  causes  the 
formation  of  this  preservative  material,  beyond  the  fact 
that  it  forms  when  healthy  wood  is  wounded  and  exposed 
to  the  air.  In  the  Coniferae  this  substance  is  not  present 
and  Frank  J  holds  that  the  infiltration  of  resin  takes  the 
place  of  the  gum.  Hartig  §  finds  a  yellowish-brown  mass 
in  the  cells  adjacent  to  wounds  in  trees.  This  mass  is 
usually  much  cracked.  He  calls  it  dried  brown  solution, 


*  Frank,  B.    Uber  die  Gummibildung  im  Holze  u.  deren  physiologische 
Bedeutung.     (Ber  d.  deut.  bot.  Ges.  18  Juli,  1884). 

t  Temme,  F.    liber  Schutz  und  Kernholz,  seine  Bildung  u.  seine  phy- 
siologische Bedeutung.     (Landw.  Jahrb.  14 :  465.     Taf.  6,  7.     1885. 

J  Frank,  B.    Die  Krankheiten  der  Pflanzen  1 :  41.     1895. 

§  Hartig,  R.    Zersetzungserscheinungen  etc.  66.    pi.  ll.flg.  7. 
34 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

and  believes  that  it  consists  of  decomposition  products  of 
wood  exposed  to  the  disintegrating  influences  of  the  outer 
air.  These  products  are  dissolved  by  water  and  penetrate 
far  into  the  tree,  bringing  about  the  characteristic  phe- 
nomena of  wound  rot.  Frank  *  claims  that  Hartig  has 
mistaken  the  nature  of  this  substance,  which  he  says  is  not 
a  humus  compound  but  wound  gum,  which  acts  as  a  pre- 
servative. A  comparison  of  Hartig' s  figure  and  the  one 
on  PI.  4,  fig.  4,  will  show  that  in  point  of  appearance  the 
substance  described  by  Hartig  and  the  one  in  Taxodium 
cells  are  alike.  I  have  also  found  such  substances  in 
wounds,  and  neither  these  nor  the  substance  in  Taxodium 
are  the  wood  gum  which  Frank  describes.  I  believe  that 
Hartig  is  right  when  he  calls  them  humus  solution,  but 
cannot  agree  that  they  are  active  in  promoting  decomposi- 
tion. It  might  be  added  that  Willkomm  f  ascribes  the 
brown  coloration  of  diseased  pine  wood  to  a  humus  com- 
pound which  he  says  is  formed  from  the  cell-walls  when 
they  begin  to  decompose. 

No  substance  corresponding  to  Frank's  wound  gum  could 
be  obtained  from  the  Taxodium.  An  aqueous  extract  of  the 
sound  wood  is  yellowish  in  color,  due  to  some  coloring 
matter  akin  to  cur  cumin.  A  number  of  analyses  made 
of  diseased  wood  failed  to  give  any  substances  which  might 
be  regarded  as  preservative.  The  sole  difference  so  far  found 
between  the  normal  wood  and  the  diseased  wood  was  the 
constant  presence  of  the  humus  compounds  described  in 
the  diseased  wood. 

There  are  numerous  instances  which  illustrate  the  preserva- 
tive and  antiseptic  properties  of  humus  compounds.  The 
preservative  powers  of  peat  deposits  are  well  known.  Peat 
is  largely  if  not  entirely  composed  of  humus  compounds  of 
one  kind  or  another.  Its  preservative  and  antiseptic  prop- 


*  Frank,  B.     Krankheiten  der  Pflanzen  1:32.     1895. 
t  Die  mikroscopischen  Feinde  des  Waldes  68. 

35 


MISSOURI    BOTANICAL    GARDEN. 

erties  have  been  attributed  to  its  humus  acids.  Thus 
Stutzer  and  Burri  *  killed  cholera  germs  in  a  quarter  of  an 
hour  with  a  decoction  of  peat.  Lyell  f  speaks  of  the  re- 
mains of  animals  and  men,  which  had  been  perfectly  pre- 
served for  many  years  in  peat  bogs.  Kerner  von  Marilaun  J 
holds  that  the  preservation  of  plant  parts  is  brought  about 
in  moors  by  humus  acids.  "  The  dead  plants  are  saturated 
with  these  acids  and  are  not  resolved  into  carbon  dioxide, 
ammonia  and  water,  but  preserve  their  form  and  weight. 
The  rapidity  of  decay  varies  inversely  as  the  quantity 
of  compounds  of  humus  acids  present."  Also  "  the  fact 
that  fossil  remains  of  Equisetums,  Lycopodiums  and 
Cycads  .  .  .  have  reached  us  in  such  good  condition, 
is  explained  by  the  presence  of  humus  acids  which  are 
found  so  universally  in  peat.  §  Ganong  ||  points  out  that 
the  scarcity  of  nitrogen  in  peat  bogs  is  due  to  the  absence  of 
bacteria  * '  caused  doubtless  by  an  actively  antiseptic  quality 
of  the  bog  water."  Trees  and  stumps  have  often  been 
found  in  bogs  perfectly  preserved.  Lyell  (1.  c.)  speaks  of 
tree-trunks  dug  out  of  Irish  bogs  and  used  for  masts,  also 
of  white  cedar  logs  in  New  England  bogs.  1f  Other 
instances  might  be  mentioned,  but  these  will  suffice  to 
show  that  the  humus  compounds  have  antiseptic  and 
preservative  properties. 

In  the  heartwood  of  the  cypress  one  finds  the  wood 
substance  being  split  up  and  destroyed.  The  decomposi- 
tion stops  after  a  time,  and  the  fungus  mycelium,  which  at 


*  Stutzer  A.,  u  R.  Burri.  Untersuchungen  iiber  die  Einwirkung  von 
Torfmull  .  .  .  auf  die  Abtotung  der  Cholerabakterien.  (Zeits.  f.  Hyg. 
u.  Inf.  Krank.  U  :  453.  1893.) 

t  Lyell,  Sir  Chas.    Principles  of  geology  722. 

|  Kerner  von  Marilaun,  A.  The  natural  history  of  plants  1 : 262  (Eng, 
edit,  by  F.  W.  Oliver).  1894. 

§  Kerner  von  Marilaun.  1.  c.  2 : 612. 

||  Ganong,  W.  F.  Upon  raised  peat  bogs  in  the  province  of  New 
Brunswick.  (Trans.  Roy.  Soc.  Canada  ii.  3  :  131.  1897.) 

f  Lyell,  Sir  Chas.    A  second  visit  to  the  United  States  33.     1850. 
36 


DISEASES    OF   TAXODIUM    AND    LIBOCEDBU8. 

first  developed  profusely,  evidently  stops  growing.  The 
threads  become  coated  with  a  brown  substance,  which  also 
fills  many  of  the  cells  around  the  area  where  active  decom- 
position has  taken  place,  and  saturates  the  cell  walls. 
This  humus  substance  is  one  of  a  class  known  to  possess 
antiseptic  properties.  These  facts  suggest  that  the  humus 
compound  described  above  may  in  part  be  the  agent  which 
limits  the  disintegrating  effects  of  the  fungus. 

ORIGIN  OF  THE  HUMUS  COMPOUND. 

The  origin  of  the  humus  compounds  is  still  a  matter  of 
some  uncertainty,  owing  to  the  intrinsic  difficulties.  Friih, 
who  probably  has  paid  more  attention  to  this  problem  than 
any  other  investigator,  says  that  we  know  as  little  about  the 
successive  stages  which  a  plant  member  passes  through, 
until  peat  is  formed,  as  we  do  of  the  processes  which  bring 
about  these  changes.*  The  process  is  essentially  a  process 
of  decay.  It  is  at  present  recognized  that  decay  may  be 
due  to  chemical  processes  as  such,  distinguished  from  those 
brought  about  through  the  agency  of  living  things. 
Where  decay,  or  more  properly  a  splitting  up  of  highly 
complex  organic  compounds  into  simpler  compounds  such 
as  carbon  dioxide,  ammonia  and  water,  takes  place  without 
the  aid  of  bacteria  or  fungi,  it  is  largely  a  process  of  oxida- 
tion. If  access  of  oxygen  is  prevented  no  decay  takes 
place.  Hartig,f  speaks  of  the  decomposition  of  plant 
members  following  death  due  to  frost,  as  a  process  due  to 
the  action  of  oxygen  on  the  dead  organic  substance ;  fungus 
mycelia  get  into  the  tissues  after  a  time  and  hasten  this  de- 
composition. Friih  J  distinguishes  two  forms  of  decomposi- 
tion not  due  to  chemical  changes  per  se  (such  as  oxidation)  ; 
these  he  calls  "  Gahrung  "  and  "  Fermententwicklung." 

*  Friih,  J.  J.    Uber  Torf  u.  Dopplerit  38. 

t  Hartig,  R.     Zersetzungserscheinungen,  etc.  65. 

J  Friih,  J.  J.    1.  c.  39. 

37 


MISSOURI   BOTANICAL    GARDEN. 

The  first  process  is  brought  about  "  through  the  direct  in- 
fluence of  the  plasma  of  a  living  fungus,  and  is  characterized 
by  an  evolution  of  heat  and  carbon  dioxide .  The  other  form  is 
caused  by  a  ferment  excreted  by  living  plants.  This  distinc- 
tion can  no  longer  be  made  to-day,  as  it  seems  probable  that 
the  first  form  of  decomposition  is  also  due  to  a  ferment. 
Since  humification  takes  place  only  under  water,  Friih  holds 
that  one  might  suppose  a  ferment  the  active  agent  in  the  for- 
mation of  peat.  But  this  cannot  be  true,  for,  if  a  ferment 
were  the  agent  forming  peat  from  vegetable  substances,  the 
process  of  humification  would  be  a  uniform  one,  that  is,  a 
given  mass  would  be  entirely  transformed  into  peat.  In  a 
bog,  however,  this  is  not  the  case,  for  there  are  alternate 
layers,  some  of  which  are  humified,  others  not.  Friih, 
therefore,  agrees  with  Einhof  who  says  that  "  lack  of  free 
oxygen,  a  high  degree  of  moisture  and  a  low  temperature, 
brought  about  by  much  moisture,  bring  about  a  decompo- 
sition of  a  peculiar  kind,  i.  e.,  the  formation  of  humus 
compounds  or  peat."  He  sums  up  as  follows:*  «'  The 
formation  of  peat  is  neither  due  to  '  Gahrung  '  nor  to  a  fer- 
ment but  consists  in  the  slow  decomposition  of  plants,  with 
the  greatest  possible  exclusion  of  oxygen  by  water,  and  at 
low  temperature.  Bacteria  have  nothing  to  do  with  the 
formation  of  peat."  This  view  of  peat  formation  is  the 
one  generally  accepted;  thus,  Shaler  f  explains  it  as 
due  to  the  arrest  of  disintegration  arising  from  the  fact 
that  the  oxygen  of  the  air  does  not  have  free  contact  with 
the  carbon,  and  thus  cannot  convert  it  into  CO2. 

This  explanation  practically  states  the  fact  that  cellulose 
and  lignin  do  change  into  a  series  of  humus  compounds, 
and  that  it  is  a  process  of  chemical  change.  It  does  not 
explain  what  that  change  is  and  why  it  should  take  place. 


*  Friih.  1.  c.  49. 

t  Staler,  N.  S.    Peat  deposits.    (16th    Rep.     Director  U.  S.  Geol. 
Survey.    4:308.     1895.) 

38 


DISEASES    OF   TAXODITJM   AND   LIBOCEDRUS. 

A  number  of  observers  still  maintain  that  fungi  or  bacteria 
are  active  in  bringing  about  humification.  Thus  Hoveler  * 
finds  that  in  the  humus  of  a  forest  the  mycelia  of  fungi 
initiate  the  process  of  humification.  These  mycelia  are 
brown  in  color  and  are  found  in  every  humus  soil.  They 
belong  to  many  different  fungi  and  are  characterized  by 
possessing  clamp  connections.  Cladosporium  humifaciens 
Eo strop,  he  regards  as  the  form  most  frequently  present. 
In  decaying  trees,  and  in  such  as  are  attacked  by  various 
fungi,  such  humus  compounds  are  frequently  present ;  they 
have  been  classed  as  decomposition  products  without  fur- 
ther statement  as  to  their  origin.  In  decaying  masses 
numerous  fungi  usually  grow  all  through  the  mass,  which 
makes  it  difficult  to  decide  what  the  true  humifying  agent 
is.  In  the  cypress  a  humus  compound  usually  appears 
in  the  cells  in  which  a  definite  fungus  mycelium  is  grow- 
ing. The  same  is  true  and  probably  more  marked  where 
the  mycelium  of  Trametes  Pini  grows  in  pine  wood.  The 
latter  turns  red-brown  very  soon  after  the  mycelium  has 
entered  the  wood,  and  examination  shows  that  this  color  is 
due  to  a  humus  compound.  No  humus  compound  is  pres- 
ent in  sound  wood.  This  behavior  of  the  compound 
makes  it  seem  probable  that  the  fungus  in  some  way  changes 
the  cell- walls,  and  that  the  humus  compound  is  one  of  the 
direct  products  of  this  change. 

FERMENTS. 

In  the  decomposition  of  wood  it  has  been  assumed  that 
ferments  take  an  active  part.  Enzymes  which  attack  cellu- 
lose and  lignified  membranes  are  known.  De  Bary  f  and 


*  Hoveler,  W.  Tiber  die  Verwerthung  des  Humus  bei  der  Eraahrung 
der  chlorophyll-fiihrenden  Pflanzen.  (Prings.,  Jahrb.  fur  wiss.  Bot. 
24  :  290.  1892.) 

t  De  Bary,  A.  Uber  einige  Sclerotinien  und  Sclerotienkrankheiten. 
(Bot.  Zg.  44:377.  1886.) 

39 


VERSI1" 


MISSOURI   BOTANICAL    GARDEN. 

Marshall-Ward  *  isolated  ferments  which  corroded  cellulose 
membranes.  Brown  and  Morris  t  discovered  a  ferment 
in  germinating  barley  grains,  and  Vignal  J  records  a  case 
of  a  ferment  secreted  by  Bacillus  mesentericus,  disso- 
ciating vegetable  cells  by  destroying  the  middle  lamella. 
The  action  of  the  wood-destroying  fungi  is  such,  that 
Hartig  and  others  have  attributed  the  decay  which 
they  bring  about  to  some  enzyme  excreted  by  the 
hyphae.  That  the  same  fungus  produces  several  such 
enzymes  must  follow  from  the  different  effects  which  the 
same  fungus  has  on  the  same  wood.  If  then  we  assume 
such  a  cytohydrolytic  enzyme  to  be  formed  by  the  Taxo- 
dium  fungus,  we  find  it  destroying  the  wood  about  a  certain 
center.  As  the  mycelium  grows  along  the  vessels  more 
readily  than  across  them,  a  long  hole  is  formed.  As 
a  result  of  the  action  of  the  fungus  on  the  cell-walls,  an 
acid  humus  compound  is  formed,  which  is  deposited  in  the 
cells  surrounding  the  center  of  fungus  activity.  It  is  not 
far  to  make  the  further  assumption  that  after  a  time  the 
amount  of  humus  compound  would  be  sufficiently  great  to 
stop  the  further  development  of  the  fungus  in  that  area. 
The  hyphae  however  pass  through  this  area  to  a  new  center, 
where  they  begin  over  again.  This  would  explain  why  the 
holes  are  approximately  of  the  same  size.  The  amount  of 
antiseptic  substance  necessary  to  prevent  further  decompo- 
sition would  be  about  the  same  in  each  area,  and  it  would 
require  the  decomposition  of  a  definite  amount  of  wood  to 
form  this  quantity.  It  may  be  objected  that  the  holes  are 
not  always  bounded  by  solid  wood,  but  often  run  together. 
This  would  be  explained  by  supposing  the  amount  of 
humus  formed  at  that  point  not  sufficient  to  overcome  the 
influence  of  the  enzyme. 

The    conditions   under   which    enzymes    are   active    are 

*  Marshall- Ward,  H.    On  a  lily  disease.     (Ann.  Bot.  2  :  346.    1888.) 
f  Brown  and  Morris.    Jour,  of  Chem.  Soc.  57  :  505.    June,  1890. 
}  Vignal.    Cont.    a   1'gtude    des  bact£riac6es.     (These.  Paris.) 
40 


DISEASES    OF   TAXODIUM   AXD    LIBOCEDRUS. 

variable.  Marshall-Ward  *  finds  that  in  a  distinctly  alkaline 
liquid  the  mycelium  of  Botrytis  will  no  longer  grow.  The 
enzymes  of  most  bacteria  are  effective  only  in  alkaline 
or  neutral  media  t  while  those  of  many  fungi  are  active 
in  distinctly  acid  media  although  growth  is  more  vigorous  in 
neutral  solutions.  J  Green  §  notes  ' '  the  possible  significance 
of  the  inhibitory  effects  of  traces  of  acid  or  alkali  in  the 
solution  in  which  the  enzyme  is  working,"  and  Smith  ||  has 
made  similar  observations.  It  is  suggested  that  the  humus 
compound  may,  because  of  its  acidity,  bring  about  condi- 
tions unfavorable  to  the  activity  of  the  enzyme  formed  in 
the  cypress  wood.  As  the  humus  compound  is  at  first  in 
liquid  form,  it  saturates  the  wood  cells  for  some  distance 
around  the  hole,  and  thus  completely  fills  the  space  where 
the  mycelium  is  growing  and  many  of  the  cells  outside  of 
this  space.  This  explains  why  the  hyphae  as  a  rule  grow 
out  from  the  holes  in  straight  lines  without  branching  much 
in  the  wood  surrounding  the  holes. 

The  enzymes  are  usually  soluble  in  cold  water,  and  can 
be  precipitated  from  a  solution  by  an  excess  of  alcohol. 
Masses  of  diseased  wood  finely  divided,  as  well  as  masses 
of  mycelium,  were  digested  with  cold  water  for  27  hours; 
then  to  four  parts  of  alcohol  one  part  of  the  extract 
was  added.  A  gray  flocculent  precipitate  was  obtained 
which  on  drying  in  a  vacuum  turned  slightly  darker.  It 
was  slightly  soluble  in  water.  Sections  of  Taxodium  wood, 
young  bean  stems,  etc.,  when  placed  in  such  a  solution 
showed  no  perceptible  change.  As  Hansen  (1.  c.)  pointed 

*  Marshall-Ward,  H.     On  a  lily  disease.     (Ann.  Bot.  2  :  319.     1889.) 
f  Fermi,  Claudio,    Weitere   Untersuchungen  tiber  die  typischen  En- 
zyme der  Micro-organismen.     (Cent,  f .  Bact.  u.  Parasitenkunde  10  : 404. 
1891.) 

%  Hansen,  A.  Die  Verflussigung  der  Gelatine  durch  Schimmelpilze. 
(Flora  n.  s.  47:88.  1889.) 

§  Green,  J.  B.     On  Vegetable  ferments.     (Ann.  Bot.  7  :  83.     1893.) 
||  Smith,  E.  F.     Sensitiveness  of  certain  parasites  to  the  acid  juices 
of  host  plants.     (Abstract  in  Bot.  Gaz.  27  : 124.    1899.) 

41 


MISSOURI    BOTANICAL    GARDEN. 

out,  this  method  of  separating  enzymes  is  very  unsatisfac- 
tory, as  it  weakens  the  enzyme  and  may  even  destroy  it.  In 
this  case  it  is  probable  that  much  of  the  precipitate  consisted 
of  soluble  humus  compounds,  and  as  these  are  likewise 
precipitated  by  alcohol  a  separation  becomes  difficult. 

As  the  humus  compound  is  insoluble  in  water  (except  a 
minute  trace)  it  is  difficult  to  add  it  to  any  culture  media. 
It  was  dissolved  in  very  weak  KOH  and  added  to  agar  and 
bouillon  tubes  which  were  inoculated  with  various  bacteria 
and  fungi.  To  a  similar  series  of  agar  and  bouillon  tubes 
the  KOH  solution  was  added  and  likewise  inoculated.  In 
this  double  series  no  additional  inhibitory  effects  due  to  the 
humus  compound  were  evident. 

The  conclusions  arrived  at  in  this  chapter  indicate  that 
the  humus  compound  found  in  the  wood  surrounding  the 
holes  is  formed  because  of  the  action  of  a  fungus  on  the 
cell-walls  of  the  wood,  and  that  it  is  probably  one  of  the 
products  effective  in  preventing  the  unlimited  spread  and 
destructive  action  of  the  disintegrating  powers  of  that 
fungus. 

AGE  OF  THE  FUNGUS. 

Taxodium  distichum  is  an  interesting  tree  in  that  it  is  one 
of  the  surviving  members  of  a  race  of  trees  which  were 
prominent  in  geologic  times.  Any  disease  which  it  is 
affected  with  may  possibly  have  come  down  to  the 
present  day  with  its  host.  But  few  fungi  are  known  in 
fossil  condition.  Unger  *  describes  mycelia  from  the  wood 
of  a  Tertiary  tree ;  Williamson  f  figures  a  fungus,  Pero- 
nosporites  antiquarius  from  a  stem  of  Lepidodendron  (the 
same  is  also  found  in  coal  beds).  Conwentz  J  found  a 
mycelium  in  fossil  wood  of  Rhizocupressinoxylon  unira- 

*  Unger,  F.    Chloris  protogaea.     1847. 

t  Williamson,  W.  C.  On  the  organization  of  fossil  plants  of  the 
coal  measures.  —  Calamites.  (Phil.  Trans.  K.  S.  L.  161 : 477.  1871.) 

$  Conwentz,    H.     Fossile    Holzer   von    Karlsdorf    am    Zobten    27. 
Danzig.     1880. 
42 


DISEASES    OF   TAXODIUM    AND    LIBOCEDRUS. 

diatum.     The  mycelium  had  clamp  connections  and  swell- 
ings like  those  of  Agaricus  melleus. 

In  accounts  given  of  Taxodium  logs  found  buried  at  va- 
rious points  *  no  mention  is  made  of  any  defect.  While  in 
southern  Louisiana  last  winter  a  number  of  sections  of 
buried  Taxodium  logs  were  obtained,  f  These  were  found 
several  miles  back  from  the  Mississippi  river  at  an  average 
depth  of  10  ft.  below  Gulf  level.  Compared  with  other 
cypress  logs  found,  these  are  not  very  old,  but  they  are 
sufficiently  far  removed  from  the  present  time  to  deserve 
notice.  In  two  of  these  logs  unmistakable  signs  of  pecki- 
ness  were  found.  There  was  very  little  mycelium,  but  a 
sufficient  number  of  hyphae  with  clamp  connections  were 
seen  to  justify  the  conclusion  that  they  were  the  same  as 
those  growing  to-day.  The  holes  were  few  in  number,  but 
were  not  to  be  mistaken.  It  is  probable  that  if  other  and 
older  logs  were  examined  more  instances  would  be  found. 
It  would  seem  therefore  that  the  disease  is  one  which  has 
extended  back  for  some  thousand  years  at  least,  and 
probably  further. 


*  Lyell,  Sir  Chas.  Travels  in  N.  A.  in  the  years  1841-2.  1 : 114.  —  He 
says  of  cypress  logs  buried  in  the  Dismal  Swamp:  "When  thrown 
down  they  are  covered  by  water,  and  never  decompose  except  the  sap.'* 

Lyell,  Sir  Chas.  A  second  visit  to  the  U.  S.  249.  (1850).  —  (Cypress 
buried  at  the  mouth  of  the  Altamaha  river.) 

Carpenter,  Wm.  Account  of  the  bituminization  of  wood  in  the 
human  era,  etc.  (Am.  Journ.  of  Sc.  &  Arts  36  :  118.  1839).  —  (Buried 
cypress  forest  at  Port  Hudson,  La.) 

Bartram,  W.  Travels  through  North  &  South  Carolina,  Georgia,  E. 
&  W.  Florida  66.  London.  1792. 

f  The  logs  were  found  at  the  following  points :  — 

No.  1 .  Standing  stump  9  ft.  below  surface,  7850ft.  back  from  river  on 
Jourdan  ave.  No.  2.  Horizontal  log,  butt  30  inches;  center  10  ft.  below 
surface,  8325  ft.  from  river  on  Jourdan  ave.  Nos.  3  &  4.  Standing  stumps 
same  locality  as  No.  1.  No.  3  had  260  rings  in  the  heart  wood.  The 
surface  where  the  samples  were  taken  reads  about  21  Cairo  datum,  mean 
Gulf  level,  21.26  C.  D.,  i.  e.  they  were  therefore  about  10  ft.  below  Gulf 
level.  See  also  Chart  No.  76  of  the  Mississippi  River  Commission,  for 
location  of  Jourdan  ave. 

43 


MISSOURI    BOTANICAL    GARDEN. 

If  one  considers  the  manner  in  which  a  fungus  disease 
attacks  plants  at  the  present  day,  one  will  find  that  closely 
related  plants  are  apt  to  be  afflicted  by  the  same  disease. 
Thus  Plasmopara  Cubensis  grows  on  a  large  number  of 
genera  of  the  Cucurbitaceae  ;  Gymnosporangium  Nidus  Avis 
(Aecidium)  on  several  genera  of  the  Pomeae  (Rosaceae) ; 
Trametes  Pini  on  several  genera  of  the  Coniferae,  and  so 
on.  Judging  by  analogy,  one  might  expect  genera  nearly 
related  to  Taxodium  to  be  diseased  similarly  to  Taxodium. 
There  are  but  a  few  genera,  closely  related  to  Taxodium , 
which  grow  at  the  present  time.  In  North  America: 
Taxodium  mucronatum  is  found  in  Mexico;  /Sequoia 
gigantea  and  $.  sempervirens ,  in  California;  Libocedrus 
decurrens,  in  California  and  Oregon;  and  the  less  closely 
related  species  of  Juniperus.  In  addition  to  these  there 
are  a  number  of  other  species  scattered  over  the  globe, 
thus  Libocedrus  Douiana  and  L.  Bidwillii  in  New 
Zealand,  Libocedrus  cupressoides  and  L.  Chilensis  in 
Chili,  also  a  dwarf  species  in  Iceland.  A  closely  related 
tree,  Glyptostrobus  Europaeus,  is  found  in  some  of  the 
southeastern  provinces  of  China.  All  of  these  trees  were 
common  over  the  whole  earth  in  Tertiary  times,  and  if  a 
disease  was  common  to  them  then,  one  might  expect  to  find 
that  to-day.  Of  the  species  enumerated,  the  Sequoias  are 
apparently  free  from  diseases  of  the  wood  *  while  Libocedrus 
decurrens  and  the  species  of  Juniperus  so  far  seen,  are  affected 
by  diseases  which  cause  local  rotting  of  the  wood  much  like 
that  of  the  cypress.  Of  the  other  trees  nothing  is  known 
so  far.  The  fungus  which  causes  the  decay  in  Libocedrus 
is  described  in  the  following,  while  that  found  in  the  trunks 
of  Juniperus  species  is  to  be  described  in  a  separate  paper 
soon  to  appear. 

*  Sargent,  C.  S.    Silva  of  North  America  10 : 140.    1896. 
44 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRU8. 

THE    "  PIN  "    DISEASE  OF  LIBOCEDRUS  DECURRENS. 
HISTORICAL. 

In  1879  Harkness  *  published  a  note  in  which  he  called 
attention  to  a  peculiar  rot  which  occurs  in  the  heart 
wood  of  the  incense  cedar,  Libocedrus  decurrens.  Mayr  f 
mentions  what  is  evidently  the  same  disease  and  describes 
it  as  follows :  "  A  certain  fungus,  Daedalea  vorax9  appears 
to  be  very  destructive,  destroying  the  heart  wood  of  stand- 
ing trees ;  the  fungus  colors  the  wood  red-brown  and  forms 
large  lens-shaped  cavities,  at  the  same  time  the  wood 
becomes  very  "  briichig."  In  1896  the  following  appeared 
in  Sargent's  Silva:  J  "  The  trunks  of  Libocedrus  decurreiis 
are  frequently  honey-combed  and  its  value  destroyed  as  a 
timber  tree  by  Daedalea  vorax,  which  destroys  rounded 
masses  of  wood,  disposed  in  long  rows,  sometimes  extend- 
ing through  the  length  of  the  trunk,  reducing  them  to  a 
cinder-like  powder."  In  the  note  published  by  Harkness 
one  is  led  to  believe  that  Daedalea  vorax  attacks  Abies 
Douglasii,  — not  Libocedrus.  Daedalea  vorax  is  reported 
as  growing  on  Libocedrus  decurrens  by  Harkness. §  In  a 
letter  received  from  Dr.  Harkness  last  year  he  says: 
* '  Daedalea  vorax  is  a  fungus  which  causes  the  rot  in  Abies 
Douglasii^  etc.  As  to  the  Libocedrus  disease  he  says : 
"  Nothing  could  be  found  except  mycelium  which  per- 
meates through  the  diseased  portion.  No  visible  signs  of 
any  spores  were  seen.  A  careful  search  fails  to  reveal 
any  of  the  fungus  either  among  the  roots  or  the  surface  of 
the  tree,  nothing  indeed  to  indicate  its  presence  until  the 
tree  has  been  felled."  He  says  furthermore  that  the  note 


*  Harkness,  H.  W.    A  foe  to  the  lumberman.     (Pacific  Rural  Press. 
Jan.  25,  1879.) 

t  Mayr,  Heinrich.     Die  Waldungen  von  Nordamerika  324.     Miinchen. 
1890. 

I  Sargent,  C.  S.     Silva  of  North  America  10 : 134.     1896. 

§  Harkness  &  Moore.     Cat.  of  Pacific  Coast  fungi  12.  (Read  before  the 
Cal.  Acad.  of  Sciences,  Feb.  2,  1880). 

45 


MISSOURI    BOTANICAL    GARDEN. 

in  the  catalogue  of  Pacific  Coast  fungi  which  records 
Daedalea  vorax  on  Libocedrus  (1.  c.)  is  an  error,  and  that 
instead  of  Libocedrus  it  ought  to  read  Abies  Douglasii. 
Mayr's  statement  is  therefore  the  only  one  ascribing  this 
disease  of  Libocedrus  to  Daedalea  vorax,  for  the  note  in 
the  Silva  was  based  on  the  statements  of  Harkness 
and  Mayr.  In  view  of  the  fact  that  Mayr's  report  has 
never  been  confirmed  I  am  inclined  to  the  belief  that 
Daedalea  vorax  has  nothing  to  do  with  the  decay  of 
Libocedrus.  This  would  leave  the  identify  of  the  fungus 
which  is  responsible  for  this  trouble  as  obscure  as  in  the 
case  of  Taxodium  distichum. 

CHARACTER  OF  THE  DISEASE. 

Specimens  of  diseased  wood  received  from  various  parts 
of  California  and  Oregon  have  the  appearance  shown  in 
Plate  2.  The  heartwood  is  full  of  lens-shaped  cavities 
filled  with  a  very  brittle  brown  material.  The  latter  is  evi- 
dently the  wood  which  formerly  filled  the  cavity,  but  has 
been  changed  and  has  shrunken  considerably.  The  cavities 
are  placed  irregularly  in  the  wood  with  their  longest  diam- 
eter parallel  to  the  wood  cells.  They  vary  considerably  in 
size,  from  1  inch  long  and  \  inch  wide  to  10  inches  long 
and  1J  inches  wide.  In  the  majority  of  cases  the  separate 
cavities  do  not  communicate  with  one  another,  but  occa- 
sionally they  do,  as  is  evident  from  the  cavities  at  the  right 
side  of  the  figure.  The  line  of  demarkation  between  sound 
wood  and  the  brown  decayed  wood  is  a  very  sharp  one. 
When  the  decayed  wood  is  removed,  the  cavities  have  a 
sharply-defined,  smooth  bounding  surface.  In  most 
respects  the  appearance  of  the  wood  is  like  that  of  diseased 
Taxodium  wood. 

OCCURRENCE. 

Concerning  the  prevalence  and   mode   of  occurrence  of 
this  disease,  only  such  facts  can  be  given  as  were  learned 
from   correspondents  —  particularly   from   Dr.    Harkness, 
46 


DISEASES    OF    TAXODIUM    AND    LIBOCEDRUS. 

Mr.  A.  J.  Johnson,  and  a  number  of  lumber  companies  in 
California,  Oregon,  and  Washington.  The  disease  is  one 
which  resembles  the  one  in  the  cypress  in  its  method  of 
growth.  The  decay  begins  somewhere  in  the  upper  part 
of  a  tree  and  proceeds  both  up  and  down,  the  lens-shaped 
cavities  appearing  at  first  as  darker  areas  in  the  wood. 
Older  trees  are  very  liable  to  be  diseased.  One  correspond- 
ent, from  southern  Washington,  says:  "  The  proportion 
of  trees  affected  is  very  large.  We  might  almost  say  that 
the  trees  are  generally  so  affected  in  this  country."  From 
Placer  Co.,  Cal.,  another  correspondent  writes :  "  Probably 
more  than  one-half  of  the  trees  are  affected  in  a  greater 
or  less  degree."  From  intermediate  points  similar  reports 
have  been  received.  Young  trees,  i.  e.,  such  as  are  under 
12  inches  in  diameter,  are  not  apt  to  be  seriously  diseased. 
Climatic  and  soil  conditions  seem  to  have  as  little  influence 
on  the  prevalence  of  the  disease,  as  they  do  in  the  case  of 
pecky  cypress.  Wherever  Ztibocedrus  decurrens  grows, 
the  defect  is  also  to  be  found,  i.  e.,  from  central  California 
northward,  as  far  as  it  has  been  possible  to  learn.  The 
diseased  wood  is  quite  durable  and  can  be  used  for  fence 
posts,  scantling,  or  for  wood  sills  in  buildings.  The 
diseased  wood  is  sold  for  $l-$3  less  than  sound  cedar, 
per  thousand  ft.  B.  M.,  depending  upon  the  degree 
of  decay.  This  is  an  indication  that  it  is  at  least 
capable  of  being  used  for  some  purposes.  It  might 
bo  mentioned  here  that  boards  cut  from  trees  of  Juni- 
perus  Virginiana  affected  with  a  similar  disease  were 
recently  pulled  off  a  barn  where  they  had  been  52  years. 
The  Stimson  Mill  Co.,  of  Ballard,  Wash.,  writes:  "We 
do  not  make  any  difference  between  sound  and  rotten 
cedar;  $8  is  the  price  for  cedar  delivered." 

NAME, 

The  only  name  which  has  been  learned  which  is  applied 
to   this  disease   is   ««  pin  rot."     The  term  "  pecky  "  has 

47 


MISSOURI    BOTANICAL    GARDEN. 

been  applied  to  a  form  of  decay  in  the  cypress  in  which  the 
wood  is  destroyed  in  local  pockets.  As  this  is  a  distinct 
form  of  wood  destruction  I  would  apply  the  term  "  pecky" 
to  all  forms  of  destruction  where  pockets  or  holes  are 
formed  as  in  the  cypress.  One  would  therefore  call  the 
affected  Libocedrus  wood  "  pecky  cedar." 

STRUCTURE  OF  DISEASED  WOOD. 

The  normal  wood  of  Libocedrus  differs  but  little  from  that 
of  Taxodium  distichum.  Penhallow  *  places  the  two  genera 
side  by  side.  The  diseased  wood  is  decidedly  different 
from  the  healthy  wood.  It  has  the  appearance  of  a  brown 
charcoal,  breaks  with  a  dull  fracture  and  when  pressed 
crumbles  into  a  fine  powder.  In  the  mortar  an  impalpable 
dust  is  formed.  In  this  respect  it  is  very  different  from 
much-rotted  cypress  wood.  In  the  latter  the  chemical 
transformation  is  far  from  uniform.  Diseased  Libocedrus 
wood  is  changed  throughout ;  both  the  spring  and  the  sum- 
mer wood  are  changed,  and  very  rapidly  at  that,  i.  e., 
there  are  no  intervening  steps  as  in  Taxodium.  A  section 
made  through  the  edge  of  a  diseased  pocket  shows  that  at 
a  certain  point  the  cells  are  brown  (PI.  4,  fig.  2).  It 
will  be  noted  that  the  color  of  fig.  2  is  the  normal  color  of 
the  wood.  Hand  in  hand  with  this  coloration  goes  a  shrink- 
age of  the  middle  lamella,  so  that  the  walls  of  the  tracheids 
become  much  thinner.  They  have  lost  all  tenacity.  If  a 
piece  of  charred  wood  is  boiled  in  water  for  a  few  moments 
it  can  be  pressed  into  any  shape  like  a  piece  of  dough. 
Sections  on  a  slide  can  be  pushed  about  so  that  the  cells 
assume  a  rhomboidal  shape,  i.  e.,  the  whole  acts  like  a  net- 
work of  fine  flexible  wire.  This  is  to  some  extent  visible  in 
PL  4,  fig.  2,  where  a  number  of  the  walls  are  much  bent, 
and  do  not  have  the  rigid  appearance  of  the  healthy  wood 


*  Penhallow,  D.  P.    Generic  characters  of  N.  A.  Taxaceae  &  Coni- 
ferae.     (Trans.  Roy.  Soc.  Canada  ii.  2 :  51.  1896.) 
48 


DISEASES    OF   TAXODIUM    AND    LIBOCEDRUS. 

(fig.  1).  The  shrinkage  of  the  wall  causes  breaks  to  ap- 
pear in  the  pits  (PL  5,  fig.  11)  and  after  a  time  in 
the  walls  (e).  The  shrinkage  in  a  large  mass  of  wood 
after  a  time  becomes  so  great  that  the  wood  breaks  at  some 
point  and  gives  rise  to  the  appearance  to  be  noted  in 
the  long  hole  at  the  left  of  the  block  in  Plate  2.  The 
three  lamellae  of  the  wood-cell  are  distinct  even  in  greatly 
"charred"  wood  (PI.  4,  fig.  2). 

The  chemical  nature  of  the  wood  cells  has  been  entirely 
changed,  and,  as  has  been  said,  the  change  from  sound 
wood  to  completely  charred  wood  is  immediate  so  far  as 
microchemical  tests  can  show.  With  dilute  KOH  the  dis- 
eased wood  swells  to  two  or  three  times  its  size  and  the 
breaks  in  the  walls  close.  A  large  per  cent,  is  soluble 
in  KOH  and  from  such  a  solution  humus  compounds  similar 
to  those  found  in  the  cypress  are  obtained.  Chlor-iodide 
of  zinc  turns  the  walls  brown.  When  treated  with  dilute 
nitric  acid  the  secondary  lamellae  gradually  dissolve  and 
there  is  left  a  skeleton  framework  composed  of  the  primary 
lamella,  the  intercellular  substance  at  the  angle,  and  the 
fine  membrane  of  the  pits  with  the  thickened  torus.  The 
solution  takes  place  very  gradually  and  can  be  followed  very 
readily  in  a  thin  section.  The  nitric  acid  evidently  dissolves 
out  the  substances  into  which  the  secondary  lamella  has 
been  changed,  leaving  the  more  resistant  primary  lamella 
intact.  From  the  HNOs  solution  a  heavy  flocculent  orange 
mass  is  precipitated  when  excess  of  water  is  added.  This 
precipitate  is  very  soluble  in  alcohol  and  acetic  acid, 
slightly  so  in  ammonia,  insoluble  in  ether,  chloroform,  ben- 
zine or  acids.  When  dissolved  in  absolute  alcohol,  and 
cooled,  no  crystals  form,  but  an  oily  substance  settles  on 
the  walls  of  the  dish  as  the  alcohol  evaporates.  No  further 
attempt  was  made  to  determine  what  this  is.  Nitric  acid 
and  potassium  chlorate  dissolve  the  entire  wood  substance. 
With  EbSO*  the  walls  turn  black  and  swell  considerably. 
Phloroglucin  and  hydrochloric  acid  stain  the  rotted  wood 

49 


MISSOURI    BOTANICAL    GARDEN. 

carmine  red  verging  toward  orange,  indicating  the  presence 
of  coniferin.  When  treated  for  twelve  hours  with  Javelle 
water  and  then  stained  with  chlor-iodide  of  zinc  the  pri- 
mary lamella  turns  light  brown ;  with  methylen  blue  it  stains 
deep  blue,  indicating  the  presence  of  pectic  substances.* 
The  skeleton  framework  obtained  after  treatment  with 
nitric  acid  stains  blue  with  cellulose  stains.  This  behavior 
towards  various  reagents  shows  that  most  of  the  cellulose 
has  been  removed  and  that  the  lignin  substances  have  been 
transformed  into  substances  readily  soluble  in  nitric  acid. 
A  number  of  chemical  analyses  were  made  of  charred 
wood,  following  the  method  given  by  Allen  f  for  determin- 
ing the  compounds  found  in  wood.  The  wood  was  finely 
rasped  and  pulverized  and  dried  at  100°  C.  After  an 
aqueous  extraction,  the  wood  was  extracted  with  alcohol 
and  then  with  ether.  8.33%  was  found  soluble  in  alcohol. 
The  dried  residue  was  hard,  and  broke  with  a  bright  frac- 
ture. It  had  all  the  attributes  of  a  resin.  Small  quanti- 
ties of  pectic  substances  were  found  present,  and  a  number 
of  other  products  which  were  not  determined.  The  rotted 
wood  does  not  restore  polarized  light. 

WOOD  BETWEEN  THE  HOLES. 

The  wood  between  the  rotted  areas  is,  as  in  Taxodium, 
perfectly  sound  as  far  as  its  structure  is  concerned.  It 
reacts  with  reagents  similarly  to  healthy  wood.  In  the 
cells  immediately  surrounding  the  diseased  spots,  especially 
in  the  wood  parenchyma  and  medullary  rays,  a  red-brown 
substance  is  always  present,  which  fills  the  cells  as  with 
plugs.  It  is  very  resistant  toward  acids  and  while  boiling 
nitric  acid  dissolves  the  wood  it  does  not  affect  this  sub- 
stance. Oxalic  acid  turns  it  black  very  quickly,  also 
potassium  bichromate  and  iron  salts.  These  reactions 


*  Mangin,  A.    Sur  la  presence  des  composes  pectiques  dans  les  v6ge- 
taux,     (Comptes  rend.  etc.  109:577.     1889.) 

t  Allen,  A.  A.    Commercial  organic  analysis  1 :323.     1898. 
50 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

would  place  it  with  the  tannins.  Hartig  found  tannin 
in  decayed  wood,  whereas  it  was  not  present  in  sound 
wood,  and  in  the  present  case  there  seems  to  be  a  similar 
instance.  What  the  origin  of  the  tannin  may  be  I  do  not 
venture  to  say. 

Aside  from  the  tannin  a  brown  humus  compound,  similar 
to  that  found  in  Taxodium,  occurs.  It  is  found  in  the 
form  of  irregular  granular  masses  which  readily  dis- 
solve in  dilute  KOH.  The  medullary  rays  in  particular 
are  filled  with  this  substance  (PI.  4,  fig.  2);  it  seems 
to  permeate  the  cell- walls,  for  these  turn  the  characteristic 
yellowish-brown  color  on  addition  of  KOH,  and  the  tra- 
cheids  become  filled  with  the  brown  liquid.  Extractions  of 
the  surrounding  wood  with  KOH  yield  considerable  quan- 
tities of  the  compound.  Nowhere  were  any  dried  plates 
found,  such  as  were  described  for  the  cypress. 

MYCELIUM  AND  SPORES. 

The  mycelium  found  in  the  diseased  Libocedrus  wood 
agrees  so  closely  in  appearance  with  that  found  in  the 
Taxodium  that  the  drawing  on  PI.  5,  fig.  1  may  represent 
it  as  well.  Few  hyphae  are  to  be  found  in  the  charred 
wood  or  the  wood  about  the  holes.  Abundant  evidence  of 
their  having  been  present  is  seen  in  the  numerous  holes 
which  puncture  the  walls  of  the  charred  wood  in  all  direc- 
tions (PI.  4,  fig.  2).  No  preference  is  shown  for  the 
pits.  The  hyphae  are  most  abundant  in  wood  away  from 
the  rotted  holes.  They  are  colorless,  branch  frequently 
and  are  provided  with  a  large  number  of  clamp  connec- 
tions. The  finest  threads  pass  through  the  walls  in  all 
directions.  Between  the  rotted  areas  the  hyphae  usually 
extend  directly  from  hole  to  hole,  just  as  in  the  Taxodium. 
In  places  the  mycelium  collects  in  large  masses  or  felts ;  in 
these  felts  the  hyphae  are  matted.  Many  crystals  of 
calcium  oxalate  give  the  whole  a  white  appearance. 

A  brown  mycelium  like  that  found  in  the  cypress  was 

51 


MISSOURI    BOTANICAL    GARDEN. 

found  In  a  number  of  cases.  How  common  this  is  cannot 
be  said,  as  the  number  of  specimens  examined  was  from 
but  a  small  number  of  trees.  The  threads  have  marked 
attachment  organs  (PL  5,  fig.  9  "  d-f ")  which  have 
been  described  under  the  cypress  disease. 

In  the  rotted  wood,  and  particularly  around  the  same,  the 
cells  are  often  filled  with  great  masses  of  spores  like  those 
seen  in  isolated  cases  in  the  cypress  (PL  5,  fig.  2).  These 
spores  are  present  in  such  numbers,  that  they  often  com- 
pletely fill  the  tracheids.  Several  spores  were  found  with 
yery  fine  hyphae  attached  (fig.  5)  and  many  showed  small 
knobs  at  one  end.  It  will  be  necessary  to  see  a  large  num- 
ber of  trees  to  determine  where  these  spores  came  from. 

LOCALIZATION. 

The  localization  of  the  diseased  areas  is  quite  as  marked 
in  Libocedrus  as  it  is  in  Taxodium.  One  may  have  a 
block  of  wood  3X3X1  in.  which  looks  perfectly  sound,  but 
when  split  longitudinally  it  may  contain  a  sharply  defined 
lenticular  hole.  It  is  suggested  that  probably  similar 
reasons  to  those  given  for  the  cypress  hold  here.  The 
investigation  with  respect  to  this  point  is  to  be  regarded  as 
but  begun.  When  it  becomes  possible  to  grow  the  fungus 
found  in  the  holes  one  may  expect  to  reach  more  decisive 
conclusions. 

SUMMARY. 

In  the  foregoing,  two  forms  of  decay  have  been  de- 
scribed, one  destroying  wood  of  Taxodium  distichum,  the 
other  of  Libocedrus  decurrens.  In  both  cases  the  wood 
is  destroyed  in  localized  areas,  which  are  surrounded  by 
apparently  sound  wood.  The  cell-walls  are  changed  into 
compounds  which  diffuse  through  the  walls  and  fill  the  cells 
surrounding  the  decayed  center ;  and  these  have  been  called 
humus  compounds.  In  both,  a  fungus  mycelium  occurs 
with  strongly  marked  characteristics,  which  flourishes 
52 


DISEASES    OF   TAXODIUM   AND    LIBOCEDRUS. 

within  the  diseased  centers  and  grows  between  these 
centers  without  affecting  the  intervening  wood.  This  wood 
can  be  utilized  for  many  purposes  even  when  much  rotted, 
and  in  neither  case  does  the  mycelium  grow  after  the  tree 
has  once  been  cut  down.  The  two  trees  thus  diseased, 
both  representatives  of  a  race  of  trees  the  majority  of 
which  are  extinct,  are  closely  related  genetically,  although 
growing  in  different  parts  of  the  country.  The  two  forms 
of  decay  differ  but  slightly,  and  not  more  than  might  be 
expected  in  two  woods  of  different  character.  Taking  those 
facts  into  consideration,  it  appears  probable  that  the  two 
diseases  are  caused  by  one  and  the  same  fungus,  the  fruiting 
form  of  which  has  not  yet  been  found. 


EXPLANATION  OF  PLATES  ILLUSTRATING  DISEASES  OF 
TAXODIUM  AND  LIBOCEDRUS. 

Plates  1,  2,  plate  4,  fig.  3,  and  the  coloring  of  plate  3, 
fig.  2,  and  plate  4,  fig.  2,  were  prepared  under  my  direction 
by  Miss  Harriet  P.  Learned. 

Plate  1.  —  1,  Branch  of  Taxodium  distichum,  showing  early  stage  of 
the  pecky  disease.  The  wood  turns  yellow  in  longitudinal  lines  (X$)» 
2,  A  block  of  Taxodium  distichum  cut  from  the  heart  of  a  tree  several 
hundred  years  old,  showing  advanced  stage  of  peckiness.  In  a  large 
number  of  trees  the  rotted  portion  is  more  yellow  than  that  shown  in  the 
figure  (XD. 

Plate  2.  —  A  block  of  Libocedrus  decurrens  showing  advanced  stage  of 
the  pecky  disease.  The  rotted  wood  has  fallen  out  from  the  holes  at  the 
tight  of  the  figure  leaving  a  smooth  surface  (XiV 

Plate  3.  —  1,  Transection  of  pecky  cypress  wood.  The  section  was 
made  so  as  to  include  some  of  the  much  rotted  wood,  seen  at  the  bottom 
of  the  figure,  also  some  of  the  sound  wood.  It  was  stained  with  phloro- 
glucin  and  HC1.  The  violet  of  the  original  section  was  somewhat  more 
marked  than  is  the  color  in  the  figure.  The  portions  staining  violet  indi- 
cate wood  which  has  not  been  affected  by  the  fungus,  those  staining 
yellow  show  where  the  coniferin  elements  have  been  extracted :  '  m ' 
medullary  rays;  *k'  cell -walls  from  which  the  coniferin  has  been  ex- 
tracted ;  *  p  '  normal  cell-wall ;  '  d '  primary  lamella  resisting  the  disinte- 
grating factor  longer  than  the  secondary  lamellae;  <h'  perforation  of 
cell-wall  made  by  fungus  hypha  (magnification  same  as  fig.  2) .  2,  Tran- 

53 


MISSOURI    BOTANICAL    GARDEN. 

section  of  pecky  cypress  wood,  showing  the  transition  from  sound  wood 
to  humus  compound,  after  staining  with  phloroglucin  and  HC1. :  '  g ' 
primary  lamella,  unaffected ;  '  p '  small  masses  of  humus  compound 
resulting  apparently  from  the  transformation  of  the  tertiary  lamella ;  « i ' 
wood  staining  yellow,  an  intermediate  stage  between  the  sound  wood  and 
the  humus  compound ;  f  h '  a  thicker  layer  of  humus  compound  than 
the  one  indicated  at  '  p ' ;  '  c '  a  still  more  advanced  stage  in  the  humus 
formation;  'e'  the  entire  cell-wall  has  been  transformed  into  the 
humus  compound;  'u'  piece  of  cell -wall  not  yet  changed  to  humus 
compound. 

Plate  4.  —  1,  Transection  of  sound  wood  of  Libocedrus  decurrens, 
showing  spring  and  summer  wood :  *  h '  brown  hypha  with  attachment 
organs ;  '  s '  spores  often  found  in  the  wood  cells.  2,  Transection  of 
diseased  wood  of  Libocedrus  decurrens^  i.  e.  wood  from  one  of  the  pockets. 
The  color  is  the  natural  color  of  the  wood.  The  medullary  ray  is  filled 
with  brown  humus  solution.  3,  Block  of  Taxodium  distichum  showing 
pecky  hole  lined  with  white  fibers,  consisting  of  pure  cellulose  (XJ)«  *, 
Two  tracheids  from  wood  surrounding  a  diseased  spot  in  Taxodium 
distichum.  The  tracheids  are  filled  with  brown  humus  compound  which 
has  cracked  in  drying. 

Plate  5.  —  1,  Mycelium  from  decayed  wood  of  Taxodium  distichum, 
showing  the  numerous  clamp  connections.  2,  Spores  from  pecky  wood 
of  Libocedrus  decurrens.  (The  line  at  the  top  is  10/i.)  3,  Portion  of  a 
tracheid  near  diseased  area  of  Taxodium  distichum.  The  pits  appear 
corroded  because  of  a  peculiar  arrangement  of  resin  globules.  (Magni- 
fication same  as  fig.  2.)  4,  Brown  chlamydospores  from  rotted  wood 
of  Taxodium  distichum.  5,  Brown  spores  from  wood  of  Taxodium  dis- 
tichum. These  are  like  the  ones  found  in  the  red  cedar.  6,  Spores  from 
wood  of  Quercus  alba  destroyed  by  Polyporus  sulphureus  (from  Will- 
iamsville,  Mo. ;  magnification  same  as  fig  6) .  7,  Spores  from  wood  of 
Taxodium  distichum,  resembling  Willkomm's  Xenodochus  ligniperda.  8, 
Minute  bodies,  which  appear  in  the  humus  compound  when  the  latter  is 
slowly  dissolved  away.  Two  views  are  represented  (magnification  same 
as  fig.  2).  9,  Mycelium  showing  attachment  organs:  '  a-c  '  from  wood 
of  Taxodium  distichum;  (  d-f  '  from  wood  of  Libocedrus  decurrens.  10, 
Longisection  of  pecky  cypress  wood,  showing  gradual  disintegration  of 
the  tracheids :  '  a '  normal  tracheid  filled  with  humus  compound ;  *  b  » 
similar  tracheid  with  colorless  mycelium ;  ( c  '  tracheid  with  pits  looking 
as  if  corroded ;  '  d  » tracheids  with  walls  which  are  beginning  to  contract ; 
'  e »  tracheid  in  which  the  walls  show  spiral  cracks;  '  f  '  and  '  g '  tracheids 
showing  final  stages  in  the  process  of  solution.  (Magnification  same 
as  fig.  1.)  11,  Longitudinal  section  through  pecky  wood  of  Libocedrus 
decurrens :  '  a '  normal  tracheid ;  '  b  '  tracheid  showing  beginning  of 
disintegration,  the  pits  show  cracks,  some  spores  are  collected  near 
a  wall ;  f  c  '  and  '  d '  tracheids  which  have  contracted  considerably,  show- 
ing cracks  in  the  pits  and  the  wall.  (Magnification  the  same  as  the  pre- 
ceding figure.) 
54 


DISEASES    OF   TAXODIUM    AND    LIBOCEDRUS. 

Plate  6.  — Upper  figure  a  pile  of  pecky  cypress  boards  at  Lutcher,  La. 
The  boards  have  been  exposed  some  time,  so  that  the  rotted  wood  has 
been  washed  from  the  holes.  The  lower  figure  is  a  photograph  of  the 
vertical  banks  of  a  ditch  on  Dauphin  St.,  Mobile,  Ala.  (in  front  of  the 
house  of  Dr.  Chas.  Mohr) .  The  bank  is  lined  with  pecky  cypress  boards, 
which  are  held  in  place  by  horizontal  braces. 

55 


OFTHE 

UNIVERSITY 


REFT.  Mo.  Box.  GARD.,  VOL.  11. 


PLATE  1 


c 


"> 


T  f  ai 


WESTERN     ENGR.    CO., 


PEUKY  CYPRESS. 


KEPT.  Mo.  Box.  GARD.,  VOL.  11. 


PLATE  2. 


PECK*   INCENSE   CEDAR. 


OF  THE 

UNIVERSITY 

OF 


KEPT.  Mo.  Box.  GARD.,  VOL.  11. 


PLATE  3. 


PECKY  CYPRESS. 


OFTHc 

UNIVERSITY 

OF 


KEPT   Mo.  Box.  GARD.,  VOL.  11. 


PLA.TK  4. 


PECKY   CYPRESS  AND  CEDAR. 


KEPT.  Mo.  Box.  GABD.,  VOL.  11. 


PLATE  5 


PECKY  CYPRESS  AND   CEDAR. 


KEPT.  Mo.  Box.  GARI>.,  VOL.  11. 


PLATE  6. 


PECKY   CYPRESS. 


U.C.  BERKELEY  LIBRARIES 


